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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.09720">arXiv:2411.09720</a> <span> [<a href="https://arxiv.org/pdf/2411.09720">pdf</a>, <a href="https://arxiv.org/format/2411.09720">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/OJCOMS.2024.3488594">10.1109/OJCOMS.2024.3488594 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Early-Scheduled Handover Preparation in 5G NR Millimeter-Wave Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Pjani%C4%87%2C+D">Dino Pjani膰</a>, <a href="/search/cs?searchtype=author&query=Sopasakis%2C+A">Alexandros Sopasakis</a>, <a href="/search/cs?searchtype=author&query=Reial%2C+A">Andres Reial</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.09720v1-abstract-short" style="display: inline;"> The handover (HO) procedure is one of the most critical functions in a cellular network driven by measurements of the user channel of the serving and neighboring cells. The success rate of the entire HO procedure is significantly affected by the preparation stage. As massive Multiple-Input Multiple-Output (MIMO) systems with large antenna arrays allow resolving finer details of channel behavior, w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09720v1-abstract-full').style.display = 'inline'; document.getElementById('2411.09720v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09720v1-abstract-full" style="display: none;"> The handover (HO) procedure is one of the most critical functions in a cellular network driven by measurements of the user channel of the serving and neighboring cells. The success rate of the entire HO procedure is significantly affected by the preparation stage. As massive Multiple-Input Multiple-Output (MIMO) systems with large antenna arrays allow resolving finer details of channel behavior, we investigate how machine learning can be applied to time series data of beam measurements in the Fifth Generation (5G) New Radio (NR) system to improve the HO procedure. This paper introduces the Early-Scheduled Handover Preparation scheme designed to enhance the robustness and efficiency of the HO procedure, particularly in scenarios involving high mobility and dense small cell deployments. Early-Scheduled Handover Preparation focuses on optimizing the timing of the HO preparation phase by leveraging machine learning techniques to predict the earliest possible trigger points for HO events. We identify a new early trigger for HO preparation and demonstrate how it can beneficially reduce the required time for HO execution reducing channel quality degradation. These insights enable a new HO preparation scheme that offers a novel, user-aware, and proactive HO decision making in MIMO scenarios incorporating mobility. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09720v1-abstract-full').style.display = 'none'; document.getElementById('2411.09720v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.19854">arXiv:2410.19854</a> <span> [<a href="https://arxiv.org/pdf/2410.19854">pdf</a>, <a href="https://arxiv.org/format/2410.19854">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> Dynamic User Grouping based on Location and Heading in 5G NR Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Pjani%C4%87%2C+D">Dino Pjani膰</a>, <a href="/search/cs?searchtype=author&query=Arslant%C3%BCrk%2C+K+E">Korkut Emre Arslant眉rk</a>, <a href="/search/cs?searchtype=author&query=Cai%2C+X">Xuesong Cai</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.19854v1-abstract-short" style="display: inline;"> User grouping based on geographic location in fifth generation (5G) New Radio (NR) systems has several applications that can significantly improve network performance, user experience, and service delivery. We demonstrate how Sounding Reference Signals channel fingerprints can be used for dynamic user grouping in a 5G NR commercial deployment based on outdoor positions and heading direction employ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.19854v1-abstract-full').style.display = 'inline'; document.getElementById('2410.19854v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.19854v1-abstract-full" style="display: none;"> User grouping based on geographic location in fifth generation (5G) New Radio (NR) systems has several applications that can significantly improve network performance, user experience, and service delivery. We demonstrate how Sounding Reference Signals channel fingerprints can be used for dynamic user grouping in a 5G NR commercial deployment based on outdoor positions and heading direction employing machine learning methods such as neural networks combined with clustering methods. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.19854v1-abstract-full').style.display = 'none'; document.getElementById('2410.19854v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.00142">arXiv:2406.00142</a> <span> [<a href="https://arxiv.org/pdf/2406.00142">pdf</a>, <a href="https://arxiv.org/format/2406.00142">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Achieving Distributed MIMO Performance with Repeater-Assisted Cellular Massive MIMO </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Willhammar%2C+S">Sara Willhammar</a>, <a href="/search/cs?searchtype=author&query=Iimori%2C+H">Hiroki Iimori</a>, <a href="/search/cs?searchtype=author&query=Vieira%2C+J">Joao Vieira</a>, <a href="/search/cs?searchtype=author&query=Sundstr%C3%B6m%2C+L">Lars Sundstr枚m</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.00142v3-abstract-short" style="display: inline;"> In what ways could cellular massive MIMO be improved? This technology has already been shown to bring huge performance gains. However, coverage holes and difficulties to transmit multiple streams to multi-antenna users because of insufficient channel rank remain issues. Distributed MIMO, also known as cell-free massive MIMO, might be the ultimate solution. However, while being a powerful technolog… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.00142v3-abstract-full').style.display = 'inline'; document.getElementById('2406.00142v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.00142v3-abstract-full" style="display: none;"> In what ways could cellular massive MIMO be improved? This technology has already been shown to bring huge performance gains. However, coverage holes and difficulties to transmit multiple streams to multi-antenna users because of insufficient channel rank remain issues. Distributed MIMO, also known as cell-free massive MIMO, might be the ultimate solution. However, while being a powerful technology, it is expensive to install backhaul, and it is a difficult problem to achieve accurate phase alignment for coherent multi-user beamforming on downlink. Another option is reflective intelligent surfaces - but they have large form factors and require a lot of training and control overhead, and probably, in practice, some form of active filtering to make them sufficiently band-selective. We propose a new approach to densification of cellular systems, envisioning repeater-assisted cellular massive MIMO, where a large numbers of physically small and cheap wireless repeaters are deployed. They receive and retransmit signals instantaneously, appearing as active scatterers. Meaning that they appear as ordinary channel scatterers but with amplification. We elaborate on the requirements of such repeaters, show that the performance of these systems could potentially approach that of distributed MIMO, and outline future research directions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.00142v3-abstract-full').style.display = 'none'; document.getElementById('2406.00142v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to IEEE Communications Magazine</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.02430">arXiv:2403.02430</a> <span> [<a href="https://arxiv.org/pdf/2403.02430">pdf</a>, <a href="https://arxiv.org/format/2403.02430">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3390/s24051385">10.3390/s24051385 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Distributed MIMO Measurements for Integrated Communication and Sensing in an Industrial Environment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Nelson%2C+C">Christian Nelson</a>, <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Fedorov%2C+A">Aleksei Fedorov</a>, <a href="/search/cs?searchtype=author&query=Deutschmann%2C+B+J+B">Benjamin J. B. Deutschmann</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.02430v1-abstract-short" style="display: inline;"> Many concepts for future generations of wireless communication systems use coherent processing of signals from many distributed antennas. The aim is to improve communication reliability, capacity, and energy efficiency and provide possibilities for new applications through integrated communication and sensing. The large bandwidths available in the higher bands have inspired much work regarding sen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.02430v1-abstract-full').style.display = 'inline'; document.getElementById('2403.02430v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.02430v1-abstract-full" style="display: none;"> Many concepts for future generations of wireless communication systems use coherent processing of signals from many distributed antennas. The aim is to improve communication reliability, capacity, and energy efficiency and provide possibilities for new applications through integrated communication and sensing. The large bandwidths available in the higher bands have inspired much work regarding sensing in the mmWave and sub-THz bands; however, the sub-6 GHz cellular bands will still be the main provider of wide cellular coverage due to the more favorable propagation conditions. In this paper, we present a measurement system and results of sub-6 GHz distributed MIMO measurements performed in an industrial environment. From the measurements, we evaluated the diversity for both large-scale and small-scale fading and characterized the link reliability. We also analyzed the possibility of multistatic sensing and positioning of users in the environment, with the initial results showing a mean-square error below 20 cm on the estimated position. Further, the results clearly showed that new channel models are needed that are spatially consistent and deal with the nonstationary channel properties among the antennas. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.02430v1-abstract-full').style.display = 'none'; document.getElementById('2403.02430v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 20 figure, Published in MDPI Sensors</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Sensors 2024, 24(5), 1385 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.15921">arXiv:2312.15921</a> <span> [<a href="https://arxiv.org/pdf/2312.15921">pdf</a>, <a href="https://arxiv.org/format/2312.15921">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Hybrid Precoder Design for Angle-of-Departure Estimation with Limited-Resolution Phase Shifters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Huang%2C+H">Huiping Huang</a>, <a href="/search/cs?searchtype=author&query=Keskin%2C+M+F">Musa Furkan Keskin</a>, <a href="/search/cs?searchtype=author&query=Wymeersch%2C+H">Henk Wymeersch</a>, <a href="/search/cs?searchtype=author&query=Cai%2C+X">Xuesong Cai</a>, <a href="/search/cs?searchtype=author&query=Wu%2C+L">Linlong Wu</a>, <a href="/search/cs?searchtype=author&query=Thunberg%2C+J">Johan Thunberg</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2312.15921v2-abstract-short" style="display: inline;"> Hybrid analog-digital beamforming stands out as a key enabler for future communication systems with a massive number of antennas. In this paper, we investigate the hybrid precoder design problem for angle-of-departure (AoD) estimation, where we take into account the practical constraint on the limited resolution of phase shifters. Our goal is to design a radio-frequency (RF) precoder and a base-ba… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.15921v2-abstract-full').style.display = 'inline'; document.getElementById('2312.15921v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.15921v2-abstract-full" style="display: none;"> Hybrid analog-digital beamforming stands out as a key enabler for future communication systems with a massive number of antennas. In this paper, we investigate the hybrid precoder design problem for angle-of-departure (AoD) estimation, where we take into account the practical constraint on the limited resolution of phase shifters. Our goal is to design a radio-frequency (RF) precoder and a base-band (BB) precoder to estimate AoD of the user with a high accuracy. To this end, we propose a two-step strategy where we first obtain the fully digital precoder that minimizes the angle error bound, and then the resulting digital precoder is decomposed into an RF precoder and a BB precoder, based on the alternating optimization and the alternating direction method of multipliers. Besides, we derive the quantization error upper bound and analyse the convergence behavior of the proposed algorithm. Numerical results demonstrate the superior performance of the proposed method over state-of-the-art baselines. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.15921v2-abstract-full').style.display = 'none'; document.getElementById('2312.15921v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">This paper has been accepted for publication in IEEE Transactions on Communications</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.02961">arXiv:2309.02961</a> <span> [<a href="https://arxiv.org/pdf/2309.02961">pdf</a>, <a href="https://arxiv.org/format/2309.02961">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computer Vision and Pattern Recognition">cs.CV</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Sound">cs.SD</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Audio and Speech Processing">eess.AS</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/JISPIN.2024.3429110">10.1109/JISPIN.2024.3429110 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> LuViRA Dataset Validation and Discussion: Comparing Vision, Radio, and Audio Sensors for Indoor Localization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Yaman%2C+I">Ilayda Yaman</a>, <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Tegler%2C+E">Erik Tegler</a>, <a href="/search/cs?searchtype=author&query=Gulin%2C+J">Jens Gulin</a>, <a href="/search/cs?searchtype=author&query=Challa%2C+N">Nikhil Challa</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Astrom%2C+K">Kalle Astrom</a>, <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.02961v2-abstract-short" style="display: inline;"> We present a unique comparative analysis, and evaluation of vision, radio, and audio based localization algorithms. We create the first baseline for the aforementioned sensors using the recently published Lund University Vision, Radio, and Audio (LuViRA) dataset, where all the sensors are synchronized and measured in the same environment. Some of the challenges of using each specific sensor for in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.02961v2-abstract-full').style.display = 'inline'; document.getElementById('2309.02961v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.02961v2-abstract-full" style="display: none;"> We present a unique comparative analysis, and evaluation of vision, radio, and audio based localization algorithms. We create the first baseline for the aforementioned sensors using the recently published Lund University Vision, Radio, and Audio (LuViRA) dataset, where all the sensors are synchronized and measured in the same environment. Some of the challenges of using each specific sensor for indoor localization tasks are highlighted. Each sensor is paired with a current state-of-the-art localization algorithm and evaluated for different aspects: localization accuracy, reliability and sensitivity to environment changes, calibration requirements, and potential system complexity. Specifically, the evaluation covers the ORB-SLAM3 algorithm for vision-based localization with an RGB-D camera, a machine-learning algorithm for radio-based localization with massive MIMO technology, and the SFS2 algorithm for audio-based localization with distributed microphones. The results can serve as a guideline and basis for further development of robust and high-precision multi-sensory localization systems, e.g., through sensor fusion, context, and environment-aware adaptation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.02961v2-abstract-full').style.display = 'none'; document.getElementById('2309.02961v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Journal of Indoor and Seamless Positioning and Navigation (2024) 1-11 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.12457">arXiv:2304.12457</a> <span> [<a href="https://arxiv.org/pdf/2304.12457">pdf</a>, <a href="https://arxiv.org/format/2304.12457">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Large Intelligent Surface Measurements for Joint Communication and Sensing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Nelson%2C+C">Christian Nelson</a>, <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Wilding%2C+T">Thomas Wilding</a>, <a href="/search/cs?searchtype=author&query=Deutschmann%2C+B">Benjamin Deutschmann</a>, <a href="/search/cs?searchtype=author&query=Witrisal%2C+K">Klaus Witrisal</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.12457v1-abstract-short" style="display: inline;"> Multiple concepts for future generations of wireless communication standards utilize coherent processing of signals from many distributed antennas. Names for these concepts include distributed MIMO, cell-free massive MIMO, XL-MIMO, and large intelligent surfaces. They aim to improve communication reliability, capacity, as well as energy efficiency and provide possibilities for new applications thr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.12457v1-abstract-full').style.display = 'inline'; document.getElementById('2304.12457v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.12457v1-abstract-full" style="display: none;"> Multiple concepts for future generations of wireless communication standards utilize coherent processing of signals from many distributed antennas. Names for these concepts include distributed MIMO, cell-free massive MIMO, XL-MIMO, and large intelligent surfaces. They aim to improve communication reliability, capacity, as well as energy efficiency and provide possibilities for new applications through joint communication and sensing. One such recently proposed solution is the concept of RadioWeaves. It proposes a new radio infrastructure for distributed MIMO with distributed internal processing, storage, and compute resources integrated into the infrastructure. The large bandwidths available in the higher bands have inspired much work regarding sensing in the mmWave- and sub-THz-bands, however, sub-6 GHz cellular bands will still be the main provider of broad cellular coverage due to the more favorable propagation conditions. In this paper, we present results from a sub-6 GHz measurement campaign targeting the non-stationary spatial channel statistics for a large RadioWeave and the temporal non-stationarity in a dynamic scenario with RadioWeaves. From the results, we also predict the possibility of multi-static sensing and positioning of users in the environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.12457v1-abstract-full').style.display = 'none'; document.getElementById('2304.12457v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 2 columns, 12 figures, IEEE European Conference on Networks and Communications & 6G Summit 2023</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.06514">arXiv:2304.06514</a> <span> [<a href="https://arxiv.org/pdf/2304.06514">pdf</a>, <a href="https://arxiv.org/format/2304.06514">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> ML-Enabled Outdoor User Positioning in 5G NR Systems via Uplink SRS Channel Estimates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=R%C3%A1th%2C+A">Andre R谩th</a>, <a href="/search/cs?searchtype=author&query=Pjani%C4%87%2C+D">Dino Pjani膰</a>, <a href="/search/cs?searchtype=author&query=Bernhardsson%2C+B">Bo Bernhardsson</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.06514v1-abstract-short" style="display: inline;"> Cellular user positioning is a promising service provided by Fifth Generation New Radio (5G NR) networks. Besides, Machine Learning (ML) techniques are foreseen to become an integrated part of 5G NR systems improving radio performance and reducing complexity. In this paper, we investigate ML techniques for positioning using 5G NR fingerprints consisting of uplink channel estimates from the physica… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06514v1-abstract-full').style.display = 'inline'; document.getElementById('2304.06514v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.06514v1-abstract-full" style="display: none;"> Cellular user positioning is a promising service provided by Fifth Generation New Radio (5G NR) networks. Besides, Machine Learning (ML) techniques are foreseen to become an integrated part of 5G NR systems improving radio performance and reducing complexity. In this paper, we investigate ML techniques for positioning using 5G NR fingerprints consisting of uplink channel estimates from the physical layer channel. We show that it is possible to use Sounding Reference Signals (SRS) channel fingerprints to provide sufficient data to infer user position. Furthermore, we show that small fully-connected moderately Deep Neural Networks, even when applied to very sparse SRS data, can achieve successful outdoor user positioning with meter-level accuracy in a commercial 5G environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06514v1-abstract-full').style.display = 'none'; document.getElementById('2304.06514v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 8 figures, Accepted to be published in IEEE International Conference on Communications 2023, Rome, Italy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.03743">arXiv:2303.03743</a> <span> [<a href="https://arxiv.org/pdf/2303.03743">pdf</a>, <a href="https://arxiv.org/format/2303.03743">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> High-Precision Machine-Learning Based Indoor Localization with Massive MIMO System </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Yaman%2C+I">Ilayda Yaman</a>, <a href="/search/cs?searchtype=author&query=Sandra%2C+M">Michiel Sandra</a>, <a href="/search/cs?searchtype=author&query=Cai%2C+X">Xuesong Cai</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.03743v1-abstract-short" style="display: inline;"> High-precision cellular-based localization is one of the key technologies for next-generation communication systems. In this paper, we investigate the potential of applying machine learning (ML) to a massive multiple-input multiple-output (MIMO) system to enhance localization accuracy. We analyze a new ML-based localization pipeline that has two parallel fully connected neural networks (FCNN). The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03743v1-abstract-full').style.display = 'inline'; document.getElementById('2303.03743v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.03743v1-abstract-full" style="display: none;"> High-precision cellular-based localization is one of the key technologies for next-generation communication systems. In this paper, we investigate the potential of applying machine learning (ML) to a massive multiple-input multiple-output (MIMO) system to enhance localization accuracy. We analyze a new ML-based localization pipeline that has two parallel fully connected neural networks (FCNN). The first FCNN takes the instantaneous spatial covariance matrix to capture angular information, while the second FCNN takes the channel impulse responses to capture delay information. We fuse the estimated coordinates of these two FCNNs for further accuracy improvement. To test the localization algorithm, we performed an indoor measurement campaign with a massive MIMO testbed at 3.7GHz. In the measured scenario, the proposed pipeline can achieve centimeter-level accuracy by combining delay and angular information. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03743v1-abstract-full').style.display = 'none'; document.getElementById('2303.03743v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.05309">arXiv:2302.05309</a> <span> [<a href="https://arxiv.org/pdf/2302.05309">pdf</a>, <a href="https://arxiv.org/format/2302.05309">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computer Vision and Pattern Recognition">cs.CV</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Sound">cs.SD</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Audio and Speech Processing">eess.AS</span> </div> </div> <p class="title is-5 mathjax"> The LuViRA Dataset: Synchronized Vision, Radio, and Audio Sensors for Indoor Localization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Yaman%2C+I">Ilayda Yaman</a>, <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+M">Martin Larsson</a>, <a href="/search/cs?searchtype=author&query=Persson%2C+P">Patrik Persson</a>, <a href="/search/cs?searchtype=author&query=Sandra%2C+M">Michiel Sandra</a>, <a href="/search/cs?searchtype=author&query=D%C3%BCrr%2C+A">Alexander D眉rr</a>, <a href="/search/cs?searchtype=author&query=Tegler%2C+E">Erik Tegler</a>, <a href="/search/cs?searchtype=author&query=Challa%2C+N">Nikhil Challa</a>, <a href="/search/cs?searchtype=author&query=Garde%2C+H">Henrik Garde</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=%C3%85str%C3%B6m%2C+K">Kalle 脜str枚m</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.05309v3-abstract-short" style="display: inline;"> We present a synchronized multisensory dataset for accurate and robust indoor localization: the Lund University Vision, Radio, and Audio (LuViRA) Dataset. The dataset includes color images, corresponding depth maps, inertial measurement unit (IMU) readings, channel response between a 5G massive multiple-input and multiple-output (MIMO) testbed and user equipment, audio recorded by 12 microphones,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.05309v3-abstract-full').style.display = 'inline'; document.getElementById('2302.05309v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.05309v3-abstract-full" style="display: none;"> We present a synchronized multisensory dataset for accurate and robust indoor localization: the Lund University Vision, Radio, and Audio (LuViRA) Dataset. The dataset includes color images, corresponding depth maps, inertial measurement unit (IMU) readings, channel response between a 5G massive multiple-input and multiple-output (MIMO) testbed and user equipment, audio recorded by 12 microphones, and accurate six degrees of freedom (6DOF) pose ground truth of 0.5 mm. We synchronize these sensors to ensure that all data is recorded simultaneously. A camera, speaker, and transmit antenna are placed on top of a slowly moving service robot, and 89 trajectories are recorded. Each trajectory includes 20 to 50 seconds of recorded sensor data and ground truth labels. Data from different sensors can be used separately or jointly to perform localization tasks, and data from the motion capture (mocap) system is used to verify the results obtained by the localization algorithms. The main aim of this dataset is to enable research on sensor fusion with the most commonly used sensors for localization tasks. Moreover, the full dataset or some parts of it can also be used for other research areas such as channel estimation, image classification, etc. Our dataset is available at: https://github.com/ilaydayaman/LuViRA_Dataset <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.05309v3-abstract-full').style.display = 'none'; document.getElementById('2302.05309v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 7 figures, Accepted to ICRA 2024</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.09599">arXiv:2211.09599</a> <span> [<a href="https://arxiv.org/pdf/2211.09599">pdf</a>, <a href="https://arxiv.org/format/2211.09599">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Fading in reflective and heavily shadowed industrial environments with large arrays </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Willhammar%2C+S">Sara Willhammar</a>, <a href="/search/cs?searchtype=author&query=Van+der+Perre%2C+L">Liesbet Van der Perre</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.09599v1-abstract-short" style="display: inline;"> One of the use cases for 5G systems and beyond is ultra-reliability low-latency communication (URLLC). An enabling technology for URLLC is massive multiple-input multiple-output (MIMO), which can increase reliability due to improved user separation, array gain and the channel hardening effect. Measurements have been performed in an operating factory environment at 3.7 GHz with a co-located massive… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.09599v1-abstract-full').style.display = 'inline'; document.getElementById('2211.09599v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.09599v1-abstract-full" style="display: none;"> One of the use cases for 5G systems and beyond is ultra-reliability low-latency communication (URLLC). An enabling technology for URLLC is massive multiple-input multiple-output (MIMO), which can increase reliability due to improved user separation, array gain and the channel hardening effect. Measurements have been performed in an operating factory environment at 3.7 GHz with a co-located massive MIMO array and a unique randomly distributed array. Channel hardening can appear when the number of antennas is increased such that the variations of channel gain (small-scale fading) is decreased and it is here quantified. The cumulative distribution function (CDF) of the channel gains then becomes steeper and its tail is reduced. This CDF is modeled and the required fading margins are quantified. By deploying a distributed array, the large-scale power variations can also be reduced, further improving reliability. The large array in this rich scattering environment, creates a more reliable channel as it approaches an independent identically distributed (i.i.d.) complex Gaussian channel, indicating that one can rethink the system design in terms of e.g. channel coding and re-transmission strategies, in order to reduce latency. To conclude, massive MIMO is a highly interesting technology for reliable connectivity in reflective and heavily shadowed industrial environments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.09599v1-abstract-full').style.display = 'none'; document.getElementById('2211.09599v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to JSAC</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.05593">arXiv:2112.05593</a> <span> [<a href="https://arxiv.org/pdf/2112.05593">pdf</a>, <a href="https://arxiv.org/format/2112.05593">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> A Review of Indoor Millimeter Wave Device-based Localization and Device-free Sensing Technologies and Applications </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Shastri%2C+A">Anish Shastri</a>, <a href="/search/cs?searchtype=author&query=Valecha%2C+N">Neharika Valecha</a>, <a href="/search/cs?searchtype=author&query=Bashirov%2C+E">Enver Bashirov</a>, <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Lentmaier%2C+M">Michael Lentmaier</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Rossi%2C+M">Michele Rossi</a>, <a href="/search/cs?searchtype=author&query=Casari%2C+P">Paolo Casari</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.05593v3-abstract-short" style="display: inline;"> The commercial availability of low-cost millimeter wave (mmWave) communication and radar devices is starting to improve the penetration of such technologies in consumer markets, paving the way for large-scale and dense deployments in fifth-generation (5G)-and-beyond as well as 6G networks. At the same time, pervasive mmWave access will enable device localization and device-free sensing with unprec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.05593v3-abstract-full').style.display = 'inline'; document.getElementById('2112.05593v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.05593v3-abstract-full" style="display: none;"> The commercial availability of low-cost millimeter wave (mmWave) communication and radar devices is starting to improve the penetration of such technologies in consumer markets, paving the way for large-scale and dense deployments in fifth-generation (5G)-and-beyond as well as 6G networks. At the same time, pervasive mmWave access will enable device localization and device-free sensing with unprecedented accuracy, especially with respect to sub-6 GHz commercial-grade devices. This paper surveys the state of the art in device-based localization and device-free sensing using mmWave communication and radar devices, with a focus on indoor deployments. We first overview key concepts about mmWave signal propagation and system design. Then, we provide a detailed account of approaches and algorithms for localization and sensing enabled by mmWaves. We consider several dimensions in our analysis, including the main objectives, techniques, and performance of each work, whether each research reached some degree of implementation, and which hardware platforms were used for this purpose. We conclude by discussing that better algorithms for consumer-grade devices, data fusion methods for dense deployments, as well as an educated application of machine learning methods are promising, relevant and timely research directions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.05593v3-abstract-full').style.display = 'none'; document.getElementById('2112.05593v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">43 pages, 13 figures. Accepted in IEEE Communications Surveys & Tutorials (IEEE COMST)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.05893">arXiv:2109.05893</a> <span> [<a href="https://arxiv.org/pdf/2109.05893">pdf</a>, <a href="https://arxiv.org/format/2109.05893">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> Learning-Based UE Classification in Millimeter-Wave Cellular Systems With Mobility </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Pjani%C4%87%2C+D">Dino Pjani膰</a>, <a href="/search/cs?searchtype=author&query=Sopasakis%2C+A">Alexandros Sopasakis</a>, <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Reial%2C+A">Andres Reial</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.05893v1-abstract-short" style="display: inline;"> Millimeter-wave cellular communication requires beamforming procedures that enable alignment of the transmitter and receiver beams as the user equipment (UE) moves. For efficient beam tracking it is advantageous to classify users according to their traffic and mobility patterns. Research to date has demonstrated efficient ways of machine learning based UE classification. Although different machine… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05893v1-abstract-full').style.display = 'inline'; document.getElementById('2109.05893v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.05893v1-abstract-full" style="display: none;"> Millimeter-wave cellular communication requires beamforming procedures that enable alignment of the transmitter and receiver beams as the user equipment (UE) moves. For efficient beam tracking it is advantageous to classify users according to their traffic and mobility patterns. Research to date has demonstrated efficient ways of machine learning based UE classification. Although different machine learning approaches have shown success, most of them are based on physical layer attributes of the received signal. This, however, imposes additional complexity and requires access to those lower layer signals. In this paper, we show that traditional supervised and even unsupervised machine learning methods can successfully be applied on higher layer channel measurement reports in order to perform UE classification, thereby reducing the complexity of the classification process. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05893v1-abstract-full').style.display = 'none'; document.getElementById('2109.05893v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for Publication in 2021 IEEE International Workshop on Machine Learning for Signal Processing, 6 Pages, 7 Figures, 1 Table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.05623">arXiv:2109.05623</a> <span> [<a href="https://arxiv.org/pdf/2109.05623">pdf</a>, <a href="https://arxiv.org/format/2109.05623">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TWC.2022.3165856">10.1109/TWC.2022.3165856 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sequential Detection and Estimation of Multipath Channel Parameters Using Belief Propagation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Leitinger%2C+E">Erik Leitinger</a>, <a href="/search/cs?searchtype=author&query=Venus%2C+A">Alexander Venus</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.05623v2-abstract-short" style="display: inline;"> This paper proposes a belief propagation (BP)-based algorithm for sequential detection and estimation of multipath component (MPC) parameters based on radio signals. Under dynamic channel conditions with moving transmitter/receiver, the number of MPCs, the MPC dispersion parameters, and the number of false alarm contributions are unknown and time-varying. We develop a Bayesian model for sequential… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05623v2-abstract-full').style.display = 'inline'; document.getElementById('2109.05623v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.05623v2-abstract-full" style="display: none;"> This paper proposes a belief propagation (BP)-based algorithm for sequential detection and estimation of multipath component (MPC) parameters based on radio signals. Under dynamic channel conditions with moving transmitter/receiver, the number of MPCs, the MPC dispersion parameters, and the number of false alarm contributions are unknown and time-varying. We develop a Bayesian model for sequential detection and estimation of MPC dispersion parameters, and represent it by a factor graph enabling the use of BP for efficient computation of the marginal posterior distributions. At each time step, a snapshot-based parametric channel estimator provides parameter estimates of a set of MPCs which are used as noisy measurements by the proposed BP-based algorithm. It performs joint probabilistic data association, and estimation of the time-varying MPC parameters and the mean number of false alarm measurements, by means of the sum-product algorithm rules. The algorithm also exploits amplitude information enabling the reliable detection of "weak" MPCs with very low component signal-to-noise ratios (SNRs). The performance of the proposed algorithm compares well to state-of-the-art algorithms for high SNR MPCs, but it significantly outperforms them for medium or low SNR MPCs. Results using real radio measurements demonstrate the excellent performance of the proposed algorithm in realistic and challenging scenarios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05623v2-abstract-full').style.display = 'none'; document.getElementById('2109.05623v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages (two column), 10 figures, IEEE Transaction on Wireless Communications</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.03273">arXiv:2109.03273</a> <span> [<a href="https://arxiv.org/pdf/2109.03273">pdf</a>, <a href="https://arxiv.org/format/2109.03273">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> LuMaMi28: Real-Time Millimeter-Wave Massive MIMO Systems with Antenna Selection </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Chung%2C+M">MinKeun Chung</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Johansson%2C+A">Andreas Johansson</a>, <a href="/search/cs?searchtype=author&query=Gunnarsson%2C+S">Sara Gunnarsson</a>, <a href="/search/cs?searchtype=author&query=Nilsson%2C+M">Martin Nilsson</a>, <a href="/search/cs?searchtype=author&query=Ying%2C+Z">Zhinong Ying</a>, <a href="/search/cs?searchtype=author&query=Zander%2C+O">Olof Zander</a>, <a href="/search/cs?searchtype=author&query=Samanta%2C+K">Kamal Samanta</a>, <a href="/search/cs?searchtype=author&query=Clifton%2C+C">Chris Clifton</a>, <a href="/search/cs?searchtype=author&query=Koimori%2C+T">Toshiyuki Koimori</a>, <a href="/search/cs?searchtype=author&query=Morita%2C+S">Shinya Morita</a>, <a href="/search/cs?searchtype=author&query=Taniguchi%2C+S">Satoshi Taniguchi</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.03273v1-abstract-short" style="display: inline;"> This paper presents LuMaMi28, a real-time 28 GHz massive multiple-input multiple-output (MIMO) testbed. In this testbed, the base station has 16 transceiver chains with a fully-digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple user equipments (UEs) with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for rea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03273v1-abstract-full').style.display = 'inline'; document.getElementById('2109.03273v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.03273v1-abstract-full" style="display: none;"> This paper presents LuMaMi28, a real-time 28 GHz massive multiple-input multiple-output (MIMO) testbed. In this testbed, the base station has 16 transceiver chains with a fully-digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple user equipments (UEs) with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for real-time antenna selection where the one with the highest channel magnitude, out of four pre-defined beams, is selected. For the beam-switchable antenna array, we consider two kinds of UE antennas, with different beam-width and different peak-gain. Based on this testbed, we provide measurement results for millimeter-wave (mmWave) massive MIMO performance in different real-life scenarios with static and mobile UEs. We explore the potential benefit of the mmWave massive MIMO systems with antenna selection based on measured channel data, and discuss the performance results through real-time measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03273v1-abstract-full').style.display = 'none'; document.getElementById('2109.03273v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 17 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.00821">arXiv:2109.00821</a> <span> [<a href="https://arxiv.org/pdf/2109.00821">pdf</a>, <a href="https://arxiv.org/format/2109.00821">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Sensing and Classification Using Massive MIMO: A Tensor Decomposition-Based Approach </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Manoj%2C+B+R">B. R. Manoj</a>, <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Gunnarsson%2C+S">Sara Gunnarsson</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.00821v1-abstract-short" style="display: inline;"> Wireless-based activity sensing has gained significant attention due to its wide range of applications. We investigate radio-based multi-class classification of human activities using massive multiple-input multiple-output (MIMO) channel measurements in line-of-sight and non line-of-sight scenarios. We propose a tensor decomposition-based algorithm to extract features by exploiting the complex cor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.00821v1-abstract-full').style.display = 'inline'; document.getElementById('2109.00821v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.00821v1-abstract-full" style="display: none;"> Wireless-based activity sensing has gained significant attention due to its wide range of applications. We investigate radio-based multi-class classification of human activities using massive multiple-input multiple-output (MIMO) channel measurements in line-of-sight and non line-of-sight scenarios. We propose a tensor decomposition-based algorithm to extract features by exploiting the complex correlation characteristics across time, frequency, and space from channel tensors formed from the measurements, followed by a neural network that learns the relationship between the input features and output target labels. Through evaluations of real measurement data, it is demonstrated that the classification accuracy using a massive MIMO array achieves significantly better results compared to the state-of-the-art even for a smaller experimental data set. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.00821v1-abstract-full').style.display = 'none'; document.getElementById('2109.00821v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted for publication in IEEE Wireless Communications Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.11738">arXiv:2107.11738</a> <span> [<a href="https://arxiv.org/pdf/2107.11738">pdf</a>, <a href="https://arxiv.org/format/2107.11738">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TVT.2023.3244653">10.1109/TVT.2023.3244653 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Power Allocation for Uplink Communications of Massive Cellular-Connected UAVs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Cai%2C+X">Xuesong Cai</a>, <a href="/search/cs?searchtype=author&query=Kov%C3%A1cs%2C+I+Z">Istv谩n Z. Kov谩cs</a>, <a href="/search/cs?searchtype=author&query=Wigard%2C+J">Jeroen Wigard</a>, <a href="/search/cs?searchtype=author&query=Amorim%2C+R">Rafhael Amorim</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Mogensen%2C+P+E">Preben E. Mogensen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.11738v3-abstract-short" style="display: inline;"> Cellular-connected unmanned aerial vehicle (UAV) has attracted a surge of research interest in both academia and industry. To support aerial user equipment (UEs) in the existing cellular networks, one promising approach is to assign a portion of the system bandwidth exclusively to the UAV-UEs. This is especially favorable for use cases where a large number of UAV-UEs are exploited, e.g., for packa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.11738v3-abstract-full').style.display = 'inline'; document.getElementById('2107.11738v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.11738v3-abstract-full" style="display: none;"> Cellular-connected unmanned aerial vehicle (UAV) has attracted a surge of research interest in both academia and industry. To support aerial user equipment (UEs) in the existing cellular networks, one promising approach is to assign a portion of the system bandwidth exclusively to the UAV-UEs. This is especially favorable for use cases where a large number of UAV-UEs are exploited, e.g., for package delivery close to a warehouse. Although the nearly line-of-sight (LoS) channels can result in higher powers received, UAVs can in turn cause severe interference to each other in the same frequency band. In this contribution, we focus on the uplink communications of massive cellular-connected UAVs. Different power allocation algorithms are proposed to either maximize the minimal spectrum efficiency (SE) or maximize the overall SE to cope with severe interference based on the successive convex approximation (SCA) principle. One of the challenges is that a UAV can affect a large area meaning that many more UAV-UEs must be considered in the optimization problem, which is essentially different from that for terrestrial UEs. The necessity of single-carrier uplink transmission further complicates the problem. Nevertheless, we find that the special property of large coherent bandwidths and coherent times of the propagation channels can be leveraged. The performances of the proposed algorithms are evaluated via extensive simulations in the full-buffer transmission mode and bursty-traffic mode. Results show that the proposed algorithms can effectively enhance the uplink SEs. This work can be considered the first attempt to deal with the interference among massive cellular-connected UAV-UEs with optimized power allocations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.11738v3-abstract-full').style.display = 'none'; document.getElementById('2107.11738v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">The final version can be found in IEEE Transactions on Vehicular Technology</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.10712">arXiv:2105.10712</a> <span> [<a href="https://arxiv.org/pdf/2105.10712">pdf</a>, <a href="https://arxiv.org/format/2105.10712">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Hardware Architecture">cs.AR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> 27.5-29.5 GHz Switched Array Sounder for Dynamic Channel Characterization: Design, Implementation and Measurements </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Bengtsson%2C+E+L">Erik L. Bengtsson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.10712v1-abstract-short" style="display: inline;"> A pre-requisite for the design of wireless systems is the understanding of the propagation channel. While a wealth of propagation knowledge exists for bands below 6 GHz, the same can not be said for bands approaching millimeter-wave frequencies. In this paper, we present the design, implementation and measurement-based verification of a re-configurable 27.5-29.5 GHz channel sounder for measuring d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10712v1-abstract-full').style.display = 'inline'; document.getElementById('2105.10712v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.10712v1-abstract-full" style="display: none;"> A pre-requisite for the design of wireless systems is the understanding of the propagation channel. While a wealth of propagation knowledge exists for bands below 6 GHz, the same can not be said for bands approaching millimeter-wave frequencies. In this paper, we present the design, implementation and measurement-based verification of a re-configurable 27.5-29.5 GHz channel sounder for measuring dynamic directional channels. Based on the switched array principle, our design is capable of characterizing 128$\times$256 dual-polarized channels with snapshot times of around 600 ms. This is in sharp contrast to measurement times on the order of tens-of-minutes with rotating horn antenna sounders. Our design lends itself to high angular resolution at both link ends with calibrated antenna arrays sampled at 2$^\circ$ and 5$^\circ$ intervals in the azimuth and elevation domains. This is complemented with a bandwidth of up to 2 GHz, enabling nanosecond-level delay resolution. The short measurement times and stable radio frequency design facilitates real-time processing and averaging of the received wavefronts to gain measurement signal-to-noise ratio and dynamic range. After disclosing the sounder design and implementation, we demonstrate its capabilities by presenting dynamic and static measurements at 28 GHz over a 1 GHz bandwidth in an office corridor environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10712v1-abstract-full').style.display = 'none'; document.getElementById('2105.10712v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">IEEE Transactions on Wireless Communications, 30 pages, 16 figures, 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.04892">arXiv:2102.04892</a> <span> [<a href="https://arxiv.org/pdf/2102.04892">pdf</a>, <a href="https://arxiv.org/ps/2102.04892">ps</a>, <a href="https://arxiv.org/format/2102.04892">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Moving Object Classification with a Sub-6 GHz Massive MIMO Array using Real Data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Manoj%2C+B+R">B. R. Manoj</a>, <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Gunnarsson%2C+S">Sara Gunnarsson</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2102.04892v1-abstract-short" style="display: inline;"> Classification between different activities in an indoor environment using wireless signals is an emerging technology for various applications, including intrusion detection, patient care, and smart home. Researchers have shown different methods to classify activities and their potential benefits by utilizing WiFi signals. In this paper, we analyze classification of moving objects by employing mac… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.04892v1-abstract-full').style.display = 'inline'; document.getElementById('2102.04892v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.04892v1-abstract-full" style="display: none;"> Classification between different activities in an indoor environment using wireless signals is an emerging technology for various applications, including intrusion detection, patient care, and smart home. Researchers have shown different methods to classify activities and their potential benefits by utilizing WiFi signals. In this paper, we analyze classification of moving objects by employing machine learning on real data from a massive multi-input-multi-output (MIMO) system in an indoor environment. We conduct measurements for different activities in both line-of-sight and non line-of-sight scenarios with a massive MIMO testbed operating at 3.7 GHz. We propose algorithms to exploit amplitude and phase-based features classification task. For the considered setup, we benchmark the classification performance and show that we can achieve up to 98% accuracy using real massive MIMO data, even with a small number of experiments. Furthermore, we demonstrate the gain in performance results with a massive MIMO system as compared with that of a limited number of antennas such as in WiFi devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.04892v1-abstract-full').style.display = 'none'; document.getElementById('2102.04892v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">To be published in proceedings of IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2021</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.01584">arXiv:2012.01584</a> <span> [<a href="https://arxiv.org/pdf/2012.01584">pdf</a>, <a href="https://arxiv.org/format/2012.01584">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Millimeter-Wave Massive MIMO Testbed with Hybrid Beamforming </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Chung%2C+M">MinKeun Chung</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Johansson%2C+A">Andreas Johansson</a>, <a href="/search/cs?searchtype=author&query=Nilsson%2C+M">Martin Nilsson</a>, <a href="/search/cs?searchtype=author&query=Zander%2C+O">Olof Zander</a>, <a href="/search/cs?searchtype=author&query=Ying%2C+Z">Zhinong Ying</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.01584v1-abstract-short" style="display: inline;"> Massive multiple-input multiple-out (MIMO) technology is vital in millimeter-wave (mmWave) bands to obtain large array gains. However, there are practical challenges, such as high hardware cost and power consumption in such systems. A promising solution to these problems is to adopt a hybrid beamforming architecture. This architecture has a much lower number of transceiver (TRx) chains than the to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.01584v1-abstract-full').style.display = 'inline'; document.getElementById('2012.01584v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.01584v1-abstract-full" style="display: none;"> Massive multiple-input multiple-out (MIMO) technology is vital in millimeter-wave (mmWave) bands to obtain large array gains. However, there are practical challenges, such as high hardware cost and power consumption in such systems. A promising solution to these problems is to adopt a hybrid beamforming architecture. This architecture has a much lower number of transceiver (TRx) chains than the total antenna number, resulting in cost- and energy-efficient systems. In this paper, we present a real-time mmWave (28 GHz) massive MIMO testbed with hybrid beamforming. This testbed has a 64-antenna/16-TRx unit for beam-selection, which can be expanded to larger array sizes in a modular way. For testing everything from baseband processing algorithms to scheduling and beam-selection in real propagation environments, we extend the capability of an existing 100-antenna/100-TRx massive MIMO testbed (below 6 GHz), built upon software-defined radio technology, to a flexible mmWave massive MIMO system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.01584v1-abstract-full').style.display = 'none'; document.getElementById('2012.01584v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">54th Asilomar Conference on Signals, Systems, and Computers, Nov. 2020</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.03213">arXiv:2008.03213</a> <span> [<a href="https://arxiv.org/pdf/2008.03213">pdf</a>, <a href="https://arxiv.org/format/2008.03213">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> 6G Wireless Systems: Vision, Requirements, Challenges, Insights, and Opportunities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Shafi%2C+M">Mansoor Shafi</a>, <a href="/search/cs?searchtype=author&query=Molisch%2C+A+F">Andreas F. Molisch</a>, <a href="/search/cs?searchtype=author&query=Dohler%2C+M">Mischa Dohler</a>, <a href="/search/cs?searchtype=author&query=Sj%C3%B6land%2C+H">Henrik Sj枚land</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2008.03213v2-abstract-short" style="display: inline;"> Mobile communications have been undergoing a generational change every ten years or so. However, the time difference between the so-called "G's" is also decreasing. While fifth-generation (5G) systems are becoming a commercial reality, there is already significant interest in systems beyond 5G, which we refer to as the sixth-generation (6G) of wireless systems. In contrast to the already published… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.03213v2-abstract-full').style.display = 'inline'; document.getElementById('2008.03213v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.03213v2-abstract-full" style="display: none;"> Mobile communications have been undergoing a generational change every ten years or so. However, the time difference between the so-called "G's" is also decreasing. While fifth-generation (5G) systems are becoming a commercial reality, there is already significant interest in systems beyond 5G, which we refer to as the sixth-generation (6G) of wireless systems. In contrast to the already published papers on the topic, we take a top-down approach to 6G. We present a holistic discussion of 6G systems beginning with lifestyle and societal changes driving the need for next generation networks. This is followed by a discussion into the technical requirements needed to enable 6G applications, based on which we dissect key challenges, as well as possibilities for practically realizable system solutions across all layers of the Open Systems Interconnection stack. Since many of the 6G applications will need access to an order-of-magnitude more spectrum, utilization of frequencies between 100 GHz and 1 THz becomes of paramount importance. As such, the 6G eco-system will feature a diverse range of frequency bands, ranging from below 6 GHz up to 1 THz. We comprehensively characterize the limitations that must be overcome to realize working systems in these bands; and provide a unique perspective on the physical, as well as higher layer challenges relating to the design of next generation core networks, new modulation and coding methods, novel multiple access techniques, antenna arrays, wave propagation, radio-frequency transceiver design, as well as real-time signal processing. We rigorously discuss the fundamental changes required in the core networks of the future that serves as a major source of latency for time-sensitive applications. While evaluating the strengths and weaknesses of key 6G technologies, we differentiate what may be achievable over the next decade, relative to what is possible. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.03213v2-abstract-full').style.display = 'none'; document.getElementById('2008.03213v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for Publication into the Proceedings of the IEEE; 32 pages, 10 figures, 5 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.06772">arXiv:2004.06772</a> <span> [<a href="https://arxiv.org/pdf/2004.06772">pdf</a>, <a href="https://arxiv.org/ps/2004.06772">ps</a>, <a href="https://arxiv.org/format/2004.06772">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/OJCOMS.2020.2987704">10.1109/OJCOMS.2020.2987704 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Channel Hardening in Massive MIMO: Model Parameters and Experimental Assessment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Gunnarsson%2C+S">Sara Gunnarsson</a>, <a href="/search/cs?searchtype=author&query=Flordelis%2C+J">Jos茅 Flordelis</a>, <a href="/search/cs?searchtype=author&query=Van+der+Perre%2C+L">Liesbet Van der Perre</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.06772v1-abstract-short" style="display: inline;"> Reliability is becoming increasingly important for many applications envisioned for future wireless systems. A technology that could improve reliability in these systems is massive MIMO (Multiple-Input Multiple-Output). One reason for this is a phenomenon called channel hardening, which means that as the number of antennas in the system increases, the variations of channel gain decrease in both th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.06772v1-abstract-full').style.display = 'inline'; document.getElementById('2004.06772v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.06772v1-abstract-full" style="display: none;"> Reliability is becoming increasingly important for many applications envisioned for future wireless systems. A technology that could improve reliability in these systems is massive MIMO (Multiple-Input Multiple-Output). One reason for this is a phenomenon called channel hardening, which means that as the number of antennas in the system increases, the variations of channel gain decrease in both the time- and frequency domain. Our analysis of channel hardening is based on a joint comparison of theory, measurements and simulations. Data from measurement campaigns including both indoor and outdoor scenarios, as well as cylindrical and planar base station arrays, are analyzed. The simulation analysis includes a comparison with the COST 2100 channel model with its massive MIMO extension. The conclusion is that the COST 2100 model is well suited to represent real scenarios, and provides a reasonable match to actual measurements up to the uncertainty of antenna patterns and user interaction. Also, the channel hardening effect in practical massive MIMO channels is less pronounced than in complex independent and identically distributed (i.i.d.) Gaussian channels, which are often considered in theoretical work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.06772v1-abstract-full').style.display = 'none'; document.getElementById('2004.06772v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to IEEE Open Journal of the Communications Society</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.01672">arXiv:2003.01672</a> <span> [<a href="https://arxiv.org/pdf/2003.01672">pdf</a>, <a href="https://arxiv.org/format/2003.01672">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Real-Time Implementation Aspects of Large Intelligent Surfaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.01672v1-abstract-short" style="display: inline;"> With the potential to provide a clean break from massive multiple-input multiple-output, large intelligent surfaces (LISs) have recently received a thrust of research interest. Various proposals have been made in the literature to define the exact functionality of LISs, ranging from fully active to largely passive solutions. Nevertheless, almost all studies in the literature investigate the fundam… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.01672v1-abstract-full').style.display = 'inline'; document.getElementById('2003.01672v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.01672v1-abstract-full" style="display: none;"> With the potential to provide a clean break from massive multiple-input multiple-output, large intelligent surfaces (LISs) have recently received a thrust of research interest. Various proposals have been made in the literature to define the exact functionality of LISs, ranging from fully active to largely passive solutions. Nevertheless, almost all studies in the literature investigate the fundamental spectral efficiency performance of these architectures. In stark contrast, this paper investigates the implementation aspects of LISs. Using the fully active LIS as the basis of our exposition, we first present a rigorous discussion on the relative merits and disadvantages of possible implementation architectures from a radio-frequency circuits and real-time processing viewpoints. We then show that a distributed architecture based on a common module interfacing a smaller number of antennas can be scalable. To avoid severe losses with analog signal distribution, multiple common modules can be interconnected via a digital nearest-neighbor network. Furthermore, we show that with such a design, the maximum backplane throughput scales with the number of served user terminals, instead of the number of antennas across the surface. The discussions in the paper can serve as a guideline toward the real-time design and development of LISs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.01672v1-abstract-full').style.display = 'none'; document.getElementById('2003.01672v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Invited Paper in the Proceedings of IEEE ICASSP 2020</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.01653">arXiv:2003.01653</a> <span> [<a href="https://arxiv.org/pdf/2003.01653">pdf</a>, <a href="https://arxiv.org/ps/2003.01653">ps</a>, <a href="https://arxiv.org/format/2003.01653">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Impact of Spatially Consistent Channels on Digital Beamforming for Millimeter-Wave Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.01653v1-abstract-short" style="display: inline;"> The premise of massive multiple-input multiple-output (MIMO) is based around coherent transmission and detection. Majority of the vast literature on massive MIMO presents performance evaluations over simplified statistical propagation models. All such models are drop-based and do not ensure continuity of channel parameters. In this paper, we quantify the impact of spatially consistent (SC) models… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.01653v1-abstract-full').style.display = 'inline'; document.getElementById('2003.01653v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.01653v1-abstract-full" style="display: none;"> The premise of massive multiple-input multiple-output (MIMO) is based around coherent transmission and detection. Majority of the vast literature on massive MIMO presents performance evaluations over simplified statistical propagation models. All such models are drop-based and do not ensure continuity of channel parameters. In this paper, we quantify the impact of spatially consistent (SC) models on beamforming for massive MIMO systems. We focus on the downlink of a 28GHz multiuser urban microcellular scenario. Using the recently standardized Third Generation Partnership Project 38.901 SC-I procedure, we evaluate the signal-to-interference-plus-noise ratio of a user equipment and the system ergodic sum spectral efficiency with zero-forcing, block diagonalization, and signal-to-leakage-plus-noise ratio beamforming. Our results disclose that at practical signal-to-noise ratio levels, SC channels yield a significant performance loss relative to the case without SC due to substantial spatial correlation across the channel parameters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.01653v1-abstract-full').style.display = 'none'; document.getElementById('2003.01653v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Invited Paper in the Proceedings of EuCAP 2020</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.10817">arXiv:2002.10817</a> <span> [<a href="https://arxiv.org/pdf/2002.10817">pdf</a>, <a href="https://arxiv.org/format/2002.10817">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Amplitude and Phase Estimation for Absolute Calibration of Massive MIMO Front-Ends </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Tian%2C+G">Guoda Tian</a>, <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2002.10817v1-abstract-short" style="display: inline;"> Massive multiple-input multiple-output (MIMO) promises significantly higher performance relative to conventional multiuser systems. However, the promised gains of massive MIMO systems rely heavily on the accuracy of the absolute front-end calibration, as well as quality of channel estimates at the base station (BS). In this paper, we analyze user equipment-aided calibration mechanism to estimate t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10817v1-abstract-full').style.display = 'inline'; document.getElementById('2002.10817v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.10817v1-abstract-full" style="display: none;"> Massive multiple-input multiple-output (MIMO) promises significantly higher performance relative to conventional multiuser systems. However, the promised gains of massive MIMO systems rely heavily on the accuracy of the absolute front-end calibration, as well as quality of channel estimates at the base station (BS). In this paper, we analyze user equipment-aided calibration mechanism to estimate the amplitude scaling and phase drift at each radio-frequency chain interfacing with the BS array. Assuming a uniform linear array at the BS and Ricean fading, we obtain the estimation parameters with moment-based (amplitude, phase) and maximum-likelihood (phase-only) estimation techniques. In stark contrast to previous works, we mathematically articulate the equivalence of the two approaches for phase estimation. Furthermore, we rigorously derive a Cramer-Rao lower bound to characterize the accuracy of the two estimators. Via numerical simulations, we evaluate the estimator performance with varying dominant line-of-sight powers, dominant angles-of-arrival, and signal-to-noise ratios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10817v1-abstract-full').style.display = 'none'; document.getElementById('2002.10817v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in the Proceedings of IEEE International Conference on Communications (ICC) 2020, Dublin, Ireland</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.11903">arXiv:2001.11903</a> <span> [<a href="https://arxiv.org/pdf/2001.11903">pdf</a>, <a href="https://arxiv.org/format/2001.11903">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> </div> </div> <p class="title is-5 mathjax"> Real-Time Deployment Aspects of C-Band and Millimeter-Wave 5G-NR Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Shafi%2C+M">Mansoor Shafi</a>, <a href="/search/cs?searchtype=author&query=Tataria%2C+H">Harsh Tataria</a>, <a href="/search/cs?searchtype=author&query=Molisch%2C+A+F">Andreas F. Molisch</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Tunnicliffe%2C+G">Geoff Tunnicliffe</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.11903v1-abstract-short" style="display: inline;"> Fifth-generation (5G) new radio (NR) deployments are being rolled out in both the C-band (3.3 - 5.0 GHz) and millimeter-wave (mmWave) band (24.5 - 29.5 GHz). For outdoor scenarios, the C-band is expected to provide wide area coverage and throughput uniformity, whereas the mmWave band is expected to provide ultra-high throughput to dedicated areas within the C-band coverage. Due to the differences… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.11903v1-abstract-full').style.display = 'inline'; document.getElementById('2001.11903v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.11903v1-abstract-full" style="display: none;"> Fifth-generation (5G) new radio (NR) deployments are being rolled out in both the C-band (3.3 - 5.0 GHz) and millimeter-wave (mmWave) band (24.5 - 29.5 GHz). For outdoor scenarios, the C-band is expected to provide wide area coverage and throughput uniformity, whereas the mmWave band is expected to provide ultra-high throughput to dedicated areas within the C-band coverage. Due to the differences in the frequency bands, both systems are expected to be designed with different transmit and receive parameters, naturally resulting in performance variations proportional to the chosen parameters. Unlike many previous works, this paper presents measurement evaluations in central Auckland, New Zealand, from a pre-commercial deployment of a single-user, single-cell 5G-NR system operating in both bands. The net throughput, coverage reliability, and channel rank are analyzed across the two bands with baseband and analog beamforming. Our results show that the C-band coverage is considerably better than mmWave, with a consistently higher channel rank. Furthermore, the spatial stationarity region (SSR) for the azimuth angles-of-departure (AODs) is characterized, and a model derived from the measured beam identities is presented. The SSR of azimuth AODs is seen to closely follow a gamma distribution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.11903v1-abstract-full').style.display = 'none'; document.getElementById('2001.11903v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">In the Proceedings of 2019 IEEE International Conference on Communications (ICC), Dublin, Ireland</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.05779">arXiv:2001.05779</a> <span> [<a href="https://arxiv.org/pdf/2001.05779">pdf</a>, <a href="https://arxiv.org/format/2001.05779">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> </div> <p class="title is-5 mathjax"> RadioWeaves for efficient connectivity: analysis andimpact of constraints in actual deployments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Van+der+Perre%2C+L">Liesbet Van der Perre</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=De+Strycker%2C+L">Lieven De Strycker</a>, <a href="/search/cs?searchtype=author&query=Bj%C3%B6rnson%2C+E">Emil Bj枚rnson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.05779v1-abstract-short" style="display: inline;"> We present a new type of wireless access infras-tructure consisting of a fabric of dispersed electronic circuitsand antennas that collectively function as a massive, distributed antenna array. We have chosen to name this new wireless infrastructure 'RadioWeaves' and anticipate they can be integrated into indoor and outdoor walls, furniture, and otherobjects, rendering them a natural part of the en… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.05779v1-abstract-full').style.display = 'inline'; document.getElementById('2001.05779v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.05779v1-abstract-full" style="display: none;"> We present a new type of wireless access infras-tructure consisting of a fabric of dispersed electronic circuitsand antennas that collectively function as a massive, distributed antenna array. We have chosen to name this new wireless infrastructure 'RadioWeaves' and anticipate they can be integrated into indoor and outdoor walls, furniture, and otherobjects, rendering them a natural part of the environment. Technologically, RadioWeaves will deploy distributed arrays to create both favorable propagation and antenna array interaction. The technology leverages on the ideas of large-scale intelligent surfaces and cell-free wireless access. Offering close to the service connectivity and computing, new grades in energy efficiency,reliability, and low latency can be reached. The new concept moreover can be scaled up easily to offer a very high capacity inspecific areas demanding so. In this paper we anticipate how two different demanding use cases can be served well by a dedicated RadioWeaves deployment: a crowd scenario and a highly reflective factory environment. A practical approach towards a RadioWeaves prototype, integrating dispersed electronics invisibly in a room environment, is introduced. We outline diverse R\&D challenges that need to be addressed to realize the great potential of the RadioWeaves technology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.05779v1-abstract-full').style.display = 'none'; document.getElementById('2001.05779v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Presented at Asilomar 2019, publication in conference proceedings accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1905.04931">arXiv:1905.04931</a> <span> [<a href="https://arxiv.org/pdf/1905.04931">pdf</a>, <a href="https://arxiv.org/ps/1905.04931">ps</a>, <a href="https://arxiv.org/format/1905.04931">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Massive MIMO Extensions to the COST 2100 Channel Model: Modeling and Validation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Flordelis%2C+J">Jose Flordelis</a>, <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1905.04931v1-abstract-short" style="display: inline;"> To enable realistic studies of massive multiple-input multiple-output systems, the COST 2100 channel model is extended based on measurements. First, the concept of a base station-side visibility region (BS-VR) is proposed to model the appearance and disappearance of clusters when using a physically-large array. We find that BS-VR lifetimes are exponentially distributed, and that the number of BS-V… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.04931v1-abstract-full').style.display = 'inline'; document.getElementById('1905.04931v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.04931v1-abstract-full" style="display: none;"> To enable realistic studies of massive multiple-input multiple-output systems, the COST 2100 channel model is extended based on measurements. First, the concept of a base station-side visibility region (BS-VR) is proposed to model the appearance and disappearance of clusters when using a physically-large array. We find that BS-VR lifetimes are exponentially distributed, and that the number of BS-VRs is Poisson distributed with intensity proportional to the sum of the array length and the mean lifetime. Simulations suggest that under certain conditions longer lifetimes can help decorrelating closely-located users. Second, the concept of a multipath component visibility region (MPC-VR) is proposed to model birth-death processes of individual MPCs at the mobile station side. We find that both MPC lifetimes and MPC-VR radii are lognormally distributed. Simulations suggest that unless MPC-VRs are applied the channel condition number is overestimated. Key statistical properties of the proposed extensions, e.g., autocorrelation functions, maximum likelihood estimators, and Cramer-Rao bounds, are derived and analyzed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.04931v1-abstract-full').style.display = 'none'; document.getElementById('1905.04931v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to IEEE Transactions of Wireless Communications</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.08260">arXiv:1903.08260</a> <span> [<a href="https://arxiv.org/pdf/1903.08260">pdf</a>, <a href="https://arxiv.org/format/1903.08260">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Signal Processing">eess.SP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TWC.2019.2908362">10.1109/TWC.2019.2908362 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Massive MIMO Optimization with Compatible Sets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Fitzgerald%2C+E">Emma Fitzgerald</a>, <a href="/search/cs?searchtype=author&query=Pi%C3%B3ro%2C+M">Micha艂 Pi贸ro</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1903.08260v2-abstract-short" style="display: inline;"> Massive multiple-input multiple-output (MIMO) is expected to be a vital component in future 5G systems. As such, there is a need for new modeling in order to investigate the performance of massive MIMO not only at the physical layer, but also higher up the networking stack. In this paper, we present general optimization models for massive MIMO, based on mixed-integer programming and compatible set… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.08260v2-abstract-full').style.display = 'inline'; document.getElementById('1903.08260v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.08260v2-abstract-full" style="display: none;"> Massive multiple-input multiple-output (MIMO) is expected to be a vital component in future 5G systems. As such, there is a need for new modeling in order to investigate the performance of massive MIMO not only at the physical layer, but also higher up the networking stack. In this paper, we present general optimization models for massive MIMO, based on mixed-integer programming and compatible sets, with both maximum ratio combing and zero forcing precoding schemes. We then apply our models to the case of joint device scheduling and power control for heterogeneous devices and traffic demands, in contrast to existing power control schemes that consider only homogeneous users and saturated scenarios. Our results show substantial benefits in terms of energy usage can be achieved without sacrificing throughput, and that both signalling overhead and the complexity of end devices can be reduced by abrogating the need for uplink power control through efficient scheduling. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.08260v2-abstract-full').style.display = 'none'; document.getElementById('1903.08260v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Wireless Communications, volume 19, issue 5, pages 2794 - 2812, 2019 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1811.04494">arXiv:1811.04494</a> <span> [<a href="https://arxiv.org/pdf/1811.04494">pdf</a>, <a href="https://arxiv.org/format/1811.04494">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Massive MIMO-based Localization and Mapping Exploiting Phase Information of Multipath Components </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Leitinger%2C+E">Erik Leitinger</a>, <a href="/search/cs?searchtype=author&query=Oskarsson%2C+M">Magnus Oskarsson</a>, <a href="/search/cs?searchtype=author&query=%C3%85str%C3%B6m%2C+K">Kalle 脜str枚m</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1811.04494v2-abstract-short" style="display: inline;"> In this paper, we present a robust multipath-based localization and mapping framework that exploits the phases of specular multipath components (MPCs) using a massive multiple-input multiple-output (MIMO) array at the base station. Utilizing the phase information related to the propagation distances of the MPCs enables the possibility of localization with extraordinary accuracy even with limited b… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.04494v2-abstract-full').style.display = 'inline'; document.getElementById('1811.04494v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1811.04494v2-abstract-full" style="display: none;"> In this paper, we present a robust multipath-based localization and mapping framework that exploits the phases of specular multipath components (MPCs) using a massive multiple-input multiple-output (MIMO) array at the base station. Utilizing the phase information related to the propagation distances of the MPCs enables the possibility of localization with extraordinary accuracy even with limited bandwidth. The specular MPC parameters along with the parameters of the noise and the dense multipath component (DMC) are tracked using an extended Kalman filter (EKF), which enables to preserve the distance-related phase changes of the MPC complex amplitudes. The DMC comprises all non-resolvable MPCs, which occur due to finite measurement aperture. The estimation of the DMC parameters enhances the estimation quality of the specular MPCs and therefore also the quality of localization and mapping. The estimated MPC propagation distances are subsequently used as input to a distance-based localization and mapping algorithm. This algorithm does not need prior knowledge about the surrounding environment and base station position. The performance is demonstrated with real radio-channel measurements using an antenna array with 128 ports at the base station side and a standard cellular signal bandwidth of 40 MHz. The results show that high accuracy localization is possible even with such a low bandwidth. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.04494v2-abstract-full').style.display = 'none'; document.getElementById('1811.04494v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 November, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages (two columns), 13 figures. This work has been submitted to the IEEE Transaction on Wireless Communications for possible publication</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1804.01690">arXiv:1804.01690</a> <span> [<a href="https://arxiv.org/pdf/1804.01690">pdf</a>, <a href="https://arxiv.org/format/1804.01690">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Channel Hardening in Massive MIMO - A Measurement Based Analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Gunnarsson%2C+S">Sara Gunnarsson</a>, <a href="/search/cs?searchtype=author&query=Flordelis%2C+J">Jose Flordelis</a>, <a href="/search/cs?searchtype=author&query=Van+der+Perre%2C+L">Liesbet Van der Perre</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1804.01690v2-abstract-short" style="display: inline;"> Wireless-controlled robots, cars and other critical applications are in need of technologies that offer high reliability and low latency. Massive MIMO, Multiple-Input Multiple-Output, is a key technology for the upcoming 5G systems and is one part of the solution to increase the reliability of wireless systems. More specifically, when increasing the number of base station antennas in a massive MIM… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01690v2-abstract-full').style.display = 'inline'; document.getElementById('1804.01690v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.01690v2-abstract-full" style="display: none;"> Wireless-controlled robots, cars and other critical applications are in need of technologies that offer high reliability and low latency. Massive MIMO, Multiple-Input Multiple-Output, is a key technology for the upcoming 5G systems and is one part of the solution to increase the reliability of wireless systems. More specifically, when increasing the number of base station antennas in a massive MIMO systems the channel variations decrease and the so-called channel hardening effect appears. This means that the variations of the channel gain in time and frequency decrease. In this paper, channel hardening in massive MIMO systems is assessed based on analysis of measurement data. For an indoor scenario, the channels are measured with a 128-port cylindrical array for nine single-antenna users. The analysis shows that in a real scenario a channel hardening of 3.2-4.6 dB, measured as a reduction of the standard deviation of the channel gain, can be expected depending on the amount of user interaction. Also, some practical implications and insights are presented. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01690v2-abstract-full').style.display = 'none'; document.getElementById('1804.01690v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to SPAWC 2018</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1801.04463">arXiv:1801.04463</a> <span> [<a href="https://arxiv.org/pdf/1801.04463">pdf</a>, <a href="https://arxiv.org/format/1801.04463">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Robotics">cs.RO</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TWC.2019.2937781">10.1109/TWC.2019.2937781 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Belief Propagation Algorithm for Multipath-Based SLAM </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Leitinger%2C+E">Erik Leitinger</a>, <a href="/search/cs?searchtype=author&query=Meyer%2C+F">Florian Meyer</a>, <a href="/search/cs?searchtype=author&query=Hlawatsch%2C+F">Franz Hlawatsch</a>, <a href="/search/cs?searchtype=author&query=Witrisal%2C+K">Klaus Witrisal</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Win%2C+M+Z">Moe Z. Win</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1801.04463v4-abstract-short" style="display: inline;"> We present a simultaneous localization and mapping (SLAM) algorithm that is based on radio signals and the association of specular multipath components (MPCs) with geometric features. Especially in indoor scenarios, robust localization from radio signals is challenging due to diffuse multipath propagation, unknown MPC-feature association, and limited visibility of features. In our approach, specul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.04463v4-abstract-full').style.display = 'inline'; document.getElementById('1801.04463v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.04463v4-abstract-full" style="display: none;"> We present a simultaneous localization and mapping (SLAM) algorithm that is based on radio signals and the association of specular multipath components (MPCs) with geometric features. Especially in indoor scenarios, robust localization from radio signals is challenging due to diffuse multipath propagation, unknown MPC-feature association, and limited visibility of features. In our approach, specular reflections at flat surfaces are described in terms of virtual anchors (VAs) that are mirror images of the physical anchors (PAs). The positions of these VAs and possibly also of the PAs are unknown. We develop a Bayesian model of the SLAM problem and represent it by a factor graph, which enables the use of belief propagation (BP) for efficient marginalization of the joint posterior distribution. The resulting BP-based SLAM algorithm detects the VAs associated with the PAs and estimates jointly the time-varying position of the mobile agent and the positions of the VAs and possibly also of the PAs, thereby leveraging the MPCs in the radio signal for improved accuracy and robustness of agent localization. The algorithm has a low computational complexity and scales well in all relevant system parameters. Experimental results using both synthetic measurements and real ultra-wideband radio signals demonstrate the excellent performance of the algorithm in challenging indoor environments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.04463v4-abstract-full').style.display = 'none'; document.getElementById('1801.04463v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages (two column), 7 figures, IEEE Transaction on Wireless Communications</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.03477">arXiv:1711.03477</a> <span> [<a href="https://arxiv.org/pdf/1711.03477">pdf</a>, <a href="https://arxiv.org/format/1711.03477">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/LWC.2018.2799863">10.1109/LWC.2018.2799863 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Achievable Rates and Training Overheads for a Measured LOS Massive MIMO Channel </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Harris%2C+P">Paul Harris</a>, <a href="/search/cs?searchtype=author&query=Hasan%2C+W+B">Wael Boukley Hasan</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Beach%2C+M">Mark Beach</a>, <a href="/search/cs?searchtype=author&query=Armour%2C+S">Simon Armour</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1711.03477v2-abstract-short" style="display: inline;"> This paper presents achievable uplink (UL) sumrate predictions for a measured line-of-sight (LOS) massive multiple-input, multiple-output (MIMO) (MMIMO) scenario and illustrates the trade-off between spatial multiplexing performance and channel de-coherence rate for an increasing number of base station (BS) antennas. In addition, an orthogonal frequency division multiplexing (OFDM) case study is f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.03477v2-abstract-full').style.display = 'inline'; document.getElementById('1711.03477v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.03477v2-abstract-full" style="display: none;"> This paper presents achievable uplink (UL) sumrate predictions for a measured line-of-sight (LOS) massive multiple-input, multiple-output (MIMO) (MMIMO) scenario and illustrates the trade-off between spatial multiplexing performance and channel de-coherence rate for an increasing number of base station (BS) antennas. In addition, an orthogonal frequency division multiplexing (OFDM) case study is formed which considers the 90% coherence time to evaluate the impact of MMIMO channel training overheads in high-speed LOS scenarios. It is shown that whilst 25% of the achievable zero-forcing (ZF) sumrate is lost when the resounding interval is increased by a factor of 4, the OFDM training overheads for a 100-antenna MMIMO BS using an LTE-like physical layer could be as low as 2% for a terminal speed of 90m/s. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.03477v2-abstract-full').style.display = 'none'; document.getElementById('1711.03477v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 February, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Wireless Communications Letters 2018 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1708.06235">arXiv:1708.06235</a> <span> [<a href="https://arxiv.org/pdf/1708.06235">pdf</a>, <a href="https://arxiv.org/format/1708.06235">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Deep Convolutional Neural Networks for Massive MIMO Fingerprint-Based Positioning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Vieira%2C+J">Joao Vieira</a>, <a href="/search/cs?searchtype=author&query=Leitinger%2C+E">Erik Leitinger</a>, <a href="/search/cs?searchtype=author&query=Sarajlic%2C+M">Muris Sarajlic</a>, <a href="/search/cs?searchtype=author&query=Li%2C+X">Xuhong Li</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1708.06235v1-abstract-short" style="display: inline;"> This paper provides an initial investigation on the application of convolutional neural networks (CNNs) for fingerprint-based positioning using measured massive MIMO channels. When represented in appropriate domains, massive MIMO channels have a sparse structure which can be efficiently learned by CNNs for positioning purposes. We evaluate the positioning accuracy of state-of-the-art CNNs with cha… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1708.06235v1-abstract-full').style.display = 'inline'; document.getElementById('1708.06235v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1708.06235v1-abstract-full" style="display: none;"> This paper provides an initial investigation on the application of convolutional neural networks (CNNs) for fingerprint-based positioning using measured massive MIMO channels. When represented in appropriate domains, massive MIMO channels have a sparse structure which can be efficiently learned by CNNs for positioning purposes. We evaluate the positioning accuracy of state-of-the-art CNNs with channel fingerprints generated from a channel model with a rich clustered structure: the COST 2100 channel model. We find that moderately deep CNNs can achieve fractional-wavelength positioning accuracies, provided that an enough representative data set is available for training. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1708.06235v1-abstract-full').style.display = 'none'; document.getElementById('1708.06235v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 August, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) 2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1704.00623">arXiv:1704.00623</a> <span> [<a href="https://arxiv.org/pdf/1704.00623">pdf</a>, <a href="https://arxiv.org/format/1704.00623">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Massive MIMO Performance - TDD Versus FDD: What Do Measurements Say? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Flordelis%2C+J">Jose Flordelis</a>, <a href="/search/cs?searchtype=author&query=Rusek%2C+F">Fredrik Rusek</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1704.00623v1-abstract-short" style="display: inline;"> Downlink beamforming in Massive MIMO either relies on uplink pilot measurements - exploiting reciprocity and TDD operation, or on the use of a predetermined grid of beams with user equipments reporting their preferred beams, mostly in FDD operation. Massive MIMO in its originally conceived form uses the first strategy, with uplink pilots, whereas there is currently significant commercial interest… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.00623v1-abstract-full').style.display = 'inline'; document.getElementById('1704.00623v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1704.00623v1-abstract-full" style="display: none;"> Downlink beamforming in Massive MIMO either relies on uplink pilot measurements - exploiting reciprocity and TDD operation, or on the use of a predetermined grid of beams with user equipments reporting their preferred beams, mostly in FDD operation. Massive MIMO in its originally conceived form uses the first strategy, with uplink pilots, whereas there is currently significant commercial interest in the second, grid-of-beams. It has been analytically shown that in isotropic scattering (independent Rayleigh fading) the first approach outperforms the second. Nevertheless there remains controversy regarding their relative performance in practice. In this contribution, the performances of these two strategies are compared using measured channel data at 2.6 GHz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.00623v1-abstract-full').style.display = 'none'; document.getElementById('1704.00623v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 April, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to IEEE Transactions on Wireless Communications, 31/Mar/2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.04723">arXiv:1703.04723</a> <span> [<a href="https://arxiv.org/pdf/1703.04723">pdf</a>, <a href="https://arxiv.org/format/1703.04723">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> Temporal Analysis of Measured LOS Massive MIMO Channels with Mobility </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Harris%2C+P">Paul Harris</a>, <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Vieira%2C+J">Joao Vieira</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Hasan%2C+W+B">Wael Boukley Hasan</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Beach%2C+M">Mark Beach</a>, <a href="/search/cs?searchtype=author&query=Armour%2C+S">Simon Armour</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1703.04723v1-abstract-short" style="display: inline;"> The first measured results for massive multiple-input, multiple-output (MIMO) performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users served by a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.04723v1-abstract-full').style.display = 'inline'; document.getElementById('1703.04723v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.04723v1-abstract-full" style="display: none;"> The first measured results for massive multiple-input, multiple-output (MIMO) performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users served by a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of outdated channel information can result in severe detection and precoding inaccuracies. For the downlink (DL) in particular, a time division duplex (TDD) configuration synonymous with massive MIMO deployments could mean only the uplink (UL) is usable in extreme cases. Therefore, it is of great interest to investigate the impact of mobility on massive MIMO performance and consider ways to combat the potential limitations. In a mobile scenario with moving cars and pedestrians, the correlation of the MIMO channel vector over time is inspected for vehicles moving up to 29 km/h. For a 100 antenna system, it is found that the channel state information (CSI) update rate requirement may increase by 7 times when compared to an 8 antenna system, whilst the power control update rate could be decreased by at least 5 times relative to a single antenna system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.04723v1-abstract-full').style.display = 'none'; document.getElementById('1703.04723v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for presentation at the 85th IEEE Vehicular Technology Conference in Sydney. 5 Pages. arXiv admin note: substantial text overlap with arXiv:1701.08818</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.00399">arXiv:1703.00399</a> <span> [<a href="https://arxiv.org/pdf/1703.00399">pdf</a>, <a href="https://arxiv.org/format/1703.00399">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> </div> <p class="title is-5 mathjax"> A Measurement Based Multilink Shadowing Model for V2V Network Simulations of Highway Scenarios </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Nilsson%2C+M+G">Mikael G. Nilsson</a>, <a href="/search/cs?searchtype=author&query=Gustafson%2C+C">Carl Gustafson</a>, <a href="/search/cs?searchtype=author&query=Abbas%2C+T">Taimoor Abbas</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1703.00399v1-abstract-short" style="display: inline;"> Shadowing from vehicles can significantly degrade the performance of vehicle-to-vehicle (V2V) communication in multilink systems, e.g., vehicular ad-hoc networks (VANETs). It is thus important to characterize and model the influence of common shadowing objects like cars properly when designing these VANETs. Despite the fact that for multilink systems it is essential to model the joint effects on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.00399v1-abstract-full').style.display = 'inline'; document.getElementById('1703.00399v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.00399v1-abstract-full" style="display: none;"> Shadowing from vehicles can significantly degrade the performance of vehicle-to-vehicle (V2V) communication in multilink systems, e.g., vehicular ad-hoc networks (VANETs). It is thus important to characterize and model the influence of common shadowing objects like cars properly when designing these VANETs. Despite the fact that for multilink systems it is essential to model the joint effects on the different links, the multilink shadowing effects of V2V channels on VANET simulations are not yet well understood. In this paper we present a measurement based analysis of multilink shadowing effects in a V2V communication system with cars as blocking objects. In particular we analyze, characterize and model the large scale fading, both regarding the autocorrelation and the joint multilink cross-correlation process, for communication at 5.9 GHz between four cars in a highway convoy scenario. The results show that it is essential to separate the instantaneous propagation condition into line-of-sight (LOS) and obstructed LOS (OLOS), by other cars, and then apply an appropriate pathloss model for each of the two cases. The choice of the pathloss model not only influences the autocorrelation but also changes the cross-correlation of the large scale fading process between different links. By this, we conclude that it is important that VANET simulators should use geometry based models, that distinguish between LOS and OLOS communication. Otherwise, the VANET simulators need to consider the cross-correlation between different communication links to achieve results close to reality. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.00399v1-abstract-full').style.display = 'none'; document.getElementById('1703.00399v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 13 figures, Preprint; submitted to IEEE Transactions on Vehicular Technology</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1701.01161">arXiv:1701.01161</a> <span> [<a href="https://arxiv.org/pdf/1701.01161">pdf</a>, <a href="https://arxiv.org/format/1701.01161">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> </div> <p class="title is-5 mathjax"> The World's First Real-Time Testbed for Massive MIMO: Design, Implementation, and Validation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Vieira%2C+J">Joao Vieira</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Harris%2C+P">Paul Harris</a>, <a href="/search/cs?searchtype=author&query=Nieman%2C+K">Karl Nieman</a>, <a href="/search/cs?searchtype=author&query=Kundargi%2C+N">Nikhil Kundargi</a>, <a href="/search/cs?searchtype=author&query=Wong%2C+I">Ian Wong</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=%C3%96wall%2C+V">Viktor 脰wall</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1701.01161v2-abstract-short" style="display: inline;"> This paper sets up a framework for designing a massive multiple-input multiple-output (MIMO) testbed by investigating hardware (HW) and system-level requirements such as processing complexity, duplexing mode and frame structure. Taking these into account, a generic system and processing partitioning is proposed which allows flexible scaling and processing distribution onto a multitude of physicall… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.01161v2-abstract-full').style.display = 'inline'; document.getElementById('1701.01161v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1701.01161v2-abstract-full" style="display: none;"> This paper sets up a framework for designing a massive multiple-input multiple-output (MIMO) testbed by investigating hardware (HW) and system-level requirements such as processing complexity, duplexing mode and frame structure. Taking these into account, a generic system and processing partitioning is proposed which allows flexible scaling and processing distribution onto a multitude of physically separated devices. Based on the given HW constraints such as maximum number of links and maximum throughput for peer-to-peer interconnections combined with processing capabilities, the framework allows to evaluate modular HW components. To verify our design approach, we present the LuMaMi (Lund University Massive MIMO) testbed which constitutes the first reconfigurable real-time HW platform for prototyping massive MIMO. Utilizing up to 100 base station antennas and more than 50 Field Programmable Gate Arrays, up to 12 user equipments are served on the same time/frequency resource using an LTE-like Orthogonal Frequency Division Multiplexing time-division duplex-based transmission scheme. Proof-of-concept tests with this system show that massive MIMO can simultaneously serve a multitude of users in a static indoor and static outdoor environment utilizing the same time/frequency resource. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.01161v2-abstract-full').style.display = 'none'; document.getElementById('1701.01161v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, accepted for publication in IEEE Access</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1610.07405">arXiv:1610.07405</a> <span> [<a href="https://arxiv.org/pdf/1610.07405">pdf</a>, <a href="https://arxiv.org/format/1610.07405">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TVT.2016.2536999">10.1109/TVT.2016.2536999 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Tracking of Wideband Multipath Components in a Vehicular Communication Scenario </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Mahler%2C+K">Kim Mahler</a>, <a href="/search/cs?searchtype=author&query=Keusgen%2C+W">Wilhelm Keusgen</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Zemen%2C+T">Thomas Zemen</a>, <a href="/search/cs?searchtype=author&query=Caire%2C+G">Giuseppe Caire</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1610.07405v1-abstract-short" style="display: inline;"> A detailed understanding of the dynamic processes of vehicular radio channels is crucial for its realistic modeling. In this paper, we present multipath components (MPCs) tracking results from a channel sounder measurement with 1 GHz bandwidth at a carrier frequency of 5.7 GHz. We describe in detail the applied algorithms and perform a tracking performance evaluation based on artificial channels a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.07405v1-abstract-full').style.display = 'inline'; document.getElementById('1610.07405v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1610.07405v1-abstract-full" style="display: none;"> A detailed understanding of the dynamic processes of vehicular radio channels is crucial for its realistic modeling. In this paper, we present multipath components (MPCs) tracking results from a channel sounder measurement with 1 GHz bandwidth at a carrier frequency of 5.7 GHz. We describe in detail the applied algorithms and perform a tracking performance evaluation based on artificial channels and on measurement data from a tunnel scenario. The tracking performance of the proposed algorithm is comparable to the tracking performance of the state-of-the-art Gaussian mixture probability hypothesis density filter, yet with a significantly lower complexity. The fluctuation of the measured channel gain is followed very well by the proposed tracking algorithm, with a power loss of only 2.5 dB. We present statistical distributions for the number of MPCs and the birth/death rate. The applied algorithms and tracking results can be used to enhance the development of geometry-based channel models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.07405v1-abstract-full').style.display = 'none'; document.getElementById('1610.07405v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 October, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Vehicular Technology, vol. 66, no. 1, pp. 15 - 25, Jan. 2017 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1610.07404">arXiv:1610.07404</a> <span> [<a href="https://arxiv.org/pdf/1610.07404">pdf</a>, <a href="https://arxiv.org/format/1610.07404">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TVT.2016.2621239">10.1109/TVT.2016.2621239 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement-Based Wideband Analysis of Dynamic Multipath Propagation in Vehicular Communication Scenarios </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Mahler%2C+K">Kim Mahler</a>, <a href="/search/cs?searchtype=author&query=Keusgen%2C+W">Wilhelm Keusgen</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Zemen%2C+T">Thomas Zemen</a>, <a href="/search/cs?searchtype=author&query=Caire%2C+G">Giuseppe Caire</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1610.07404v1-abstract-short" style="display: inline;"> Realistic propagation modeling requires a detailed understanding and characterization of the radio channel properties. This paper is based on channel sounder measurements with 1 GHz bandwidth at a carrier frequency of 5.7 GHz and particular tracking methods. We present statistical models for the number of, birth rate, lifetime, excess delay and relative Doppler frequency of individual multipath co… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.07404v1-abstract-full').style.display = 'inline'; document.getElementById('1610.07404v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1610.07404v1-abstract-full" style="display: none;"> Realistic propagation modeling requires a detailed understanding and characterization of the radio channel properties. This paper is based on channel sounder measurements with 1 GHz bandwidth at a carrier frequency of 5.7 GHz and particular tracking methods. We present statistical models for the number of, birth rate, lifetime, excess delay and relative Doppler frequency of individual multipath components (MPCs). Our findings are concluded from 72 measurement runs in eight relevant vehicular communication scenarios and reveal wide insights into the dynamic propagation process in vehicular communication scenarios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.07404v1-abstract-full').style.display = 'none'; document.getElementById('1610.07404v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 October, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Vehicular Technology, vol. 66, no. 6, pp. 4657 - 4667, June 2017 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.05156">arXiv:1606.05156</a> <span> [<a href="https://arxiv.org/pdf/1606.05156">pdf</a>, <a href="https://arxiv.org/format/1606.05156">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applications">stat.AP</span> </div> </div> <p class="title is-5 mathjax"> Reciprocity Calibration for Massive MIMO: Proposal, Modeling and Validation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Vieira%2C+J">Joao Vieira</a>, <a href="/search/cs?searchtype=author&query=Rusek%2C+F">Fredrik Rusek</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Malkowsky%2C+S">Steffen Malkowsky</a>, <a href="/search/cs?searchtype=author&query=Liu%2C+L">Liang Liu</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1606.05156v3-abstract-short" style="display: inline;"> This paper presents a mutual coupling based calibration method for time-division-duplex massive MIMO systems, which enables downlink precoding based on uplink channel estimates. The entire calibration procedure is carried out solely at the base station (BS) side by sounding all BS antenna pairs. An Expectation-Maximization (EM) algorithm is derived, which processes the measured channels in order t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.05156v3-abstract-full').style.display = 'inline'; document.getElementById('1606.05156v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.05156v3-abstract-full" style="display: none;"> This paper presents a mutual coupling based calibration method for time-division-duplex massive MIMO systems, which enables downlink precoding based on uplink channel estimates. The entire calibration procedure is carried out solely at the base station (BS) side by sounding all BS antenna pairs. An Expectation-Maximization (EM) algorithm is derived, which processes the measured channels in order to estimate calibration coefficients. The EM algorithm outperforms current state-of-the-art narrow-band calibration schemes in a mean squared error (MSE) and sum-rate capacity sense. Like its predecessors, the EM algorithm is general in the sense that it is not only suitable to calibrate a co-located massive MIMO BS, but also very suitable for calibrating multiple BSs in distributed MIMO systems. The proposed method is validated with experimental evidence obtained from a massive MIMO testbed. In addition, we address the estimated narrow-band calibration coefficients as a stochastic process across frequency, and study the subspace of this process based on measurement data. With the insights of this study, we propose an estimator which exploits the structure of the process in order to reduce the calibration error across frequency. A model for the calibration error is also proposed based on the asymptotic properties of the estimator, and is validated with measurement results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.05156v3-abstract-full').style.display = 'none'; document.getElementById('1606.05156v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to IEEE Transactions on Wireless Communications, 21/Feb/2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1507.05994">arXiv:1507.05994</a> <span> [<a href="https://arxiv.org/pdf/1507.05994">pdf</a>, <a href="https://arxiv.org/ps/1507.05994">ps</a>, <a href="https://arxiv.org/format/1507.05994">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TCOMM.2015.2462350">10.1109/TCOMM.2015.2462350 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Massive MIMO in Real Propagation Environments: Do All Antennas Contribute Equally? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1507.05994v1-abstract-short" style="display: inline;"> Massive MIMO can greatly increase both spectral and transmit-energy efficiency. This is achieved by allowing the number of antennas and RF chains to grow very large. However, the challenges include high system complexity and hardware energy consumption. Here we investigate the possibilities to reduce the required number of RF chains, by performing antenna selection. While this approach is not a ve… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.05994v1-abstract-full').style.display = 'inline'; document.getElementById('1507.05994v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1507.05994v1-abstract-full" style="display: none;"> Massive MIMO can greatly increase both spectral and transmit-energy efficiency. This is achieved by allowing the number of antennas and RF chains to grow very large. However, the challenges include high system complexity and hardware energy consumption. Here we investigate the possibilities to reduce the required number of RF chains, by performing antenna selection. While this approach is not a very effective strategy for theoretical independent Rayleigh fading channels, a substantial reduction in the number of RF chains can be achieved for real massive MIMO channels, without significant performance loss. We evaluate antenna selection performance on measured channels at 2.6 GHz, using a linear and a cylindrical array, both having 128 elements. Sum-rate maximization is used as the criterion for antenna selection. A selection scheme based on convex optimization is nearly optimal and used as a benchmark. The achieved sum-rate is compared with that of a very simple scheme that selects the antennas with the highest received power. The power-based scheme gives performance close to the convex optimization scheme, for the measured channels. This observation indicates a potential for significant reductions of massive MIMO implementation complexity, by reducing the number of RF chains and performing antenna selection using simple algorithms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.05994v1-abstract-full').style.display = 'none'; document.getElementById('1507.05994v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 July, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to IEEE Transactions on Communications</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1504.03977">arXiv:1504.03977</a> <span> [<a href="https://arxiv.org/pdf/1504.03977">pdf</a>, <a href="https://arxiv.org/format/1504.03977">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/LWC.2015.2463274">10.1109/LWC.2015.2463274 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Statistical Modeling and Estimation of Censored Pathloss Data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Gustafson%2C+C">Carl Gustafson</a>, <a href="/search/cs?searchtype=author&query=Abbas%2C+T">Taimoor Abbas</a>, <a href="/search/cs?searchtype=author&query=Bolin%2C+D">David Bolin</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1504.03977v3-abstract-short" style="display: inline;"> Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the channel, which can cause measurement samples to be truncated or censored. If the information about the censored samples are not included in the estimation method, as… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.03977v3-abstract-full').style.display = 'inline'; document.getElementById('1504.03977v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1504.03977v3-abstract-full" style="display: none;"> Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the channel, which can cause measurement samples to be truncated or censored. If the information about the censored samples are not included in the estimation method, as in ordinary least squares estimation, it can result in biased estimation of both the pathloss exponent and the large scale fading. This can be solved by applying a Tobit maximum-likelihood estimator, which provides consistent estimates for the pathloss parameters. This letter provides information about the Tobit maximum-likelihood estimator and its asymptotic variance under certain conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.03977v3-abstract-full').style.display = 'none'; document.getElementById('1504.03977v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 April, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 3 figures. Published in IEEE Wireless Communication Letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Wireless Communications Letters, vol. 4, no. 5, pp. 569-572, Oct. 2015 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1410.4187">arXiv:1410.4187</a> <span> [<a href="https://arxiv.org/pdf/1410.4187">pdf</a>, <a href="https://arxiv.org/format/1410.4187">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TAP.2015.2428280">10.1109/TAP.2015.2428280 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Simulation and Measurement Based Vehicle-to-Vehicle Channel Characterization: Accuracy and Constraint Analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Abbas%2C+T">Taimoor Abbas</a>, <a href="/search/cs?searchtype=author&query=Nuckelt%2C+J">J枚rg Nuckelt</a>, <a href="/search/cs?searchtype=author&query=K%C3%BCrner%2C+T">Thomas K眉rner</a>, <a href="/search/cs?searchtype=author&query=Zemen%2C+T">Thomas Zemen</a>, <a href="/search/cs?searchtype=author&query=Mecklenbr%C3%A4uker%2C+C">Christoph Mecklenbr盲uker</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1410.4187v1-abstract-short" style="display: inline;"> In this paper, a deterministic channel model for vehicle-to-vehicle (V2V) communication, is compared against channel measurement data collected during a V2V channel measurement campaign using a channel sounder. Channel metrics such as channel gain, delay and Doppler spreads, eigenvalue decomposition and antenna correlations are derived from the ray tracing (RT) simulations as well as from the meas… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.4187v1-abstract-full').style.display = 'inline'; document.getElementById('1410.4187v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1410.4187v1-abstract-full" style="display: none;"> In this paper, a deterministic channel model for vehicle-to-vehicle (V2V) communication, is compared against channel measurement data collected during a V2V channel measurement campaign using a channel sounder. Channel metrics such as channel gain, delay and Doppler spreads, eigenvalue decomposition and antenna correlations are derived from the ray tracing (RT) simulations as well as from the measurement data obtained from two different measurements in an urban four-way intersection scenario. The channel metrics are compared separately for line-of-sight (LOS) and non-LOS (NLOS) situation. Most power contributions arise from the LOS component (if present) as well as from multipaths with single bounce reflections. Measurement and simulation results show a very good agreement in the presence of LOS, as most of the received power is contributed from the LOS component. In NLOS, the difference is large because the ray tracer is unable to capture some of the multi bounced propagation paths that are present in the measurements. Despite the limitations of the ray-based propagation model identified in this work, the model is suitable to characterize the channel properties in a sufficient manner. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.4187v1-abstract-full').style.display = 'none'; document.getElementById('1410.4187v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 October, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 20 figures, Submitted for publication and is under review in IEEE Transactions on Antennas and Propagation, 2014</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Antennas and Propagation, Vol. 63, Issue 7, 2015 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1403.3376">arXiv:1403.3376</a> <span> [<a href="https://arxiv.org/pdf/1403.3376">pdf</a>, <a href="https://arxiv.org/ps/1403.3376">ps</a>, <a href="https://arxiv.org/format/1403.3376">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TWC.2015.2414413">10.1109/TWC.2015.2414413 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Massive MIMO performance evaluation based on measured propagation data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Rusek%2C+F">Fredrik Rusek</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1403.3376v3-abstract-short" style="display: inline;"> Massive MIMO, also known as very-large MIMO or large-scale antenna systems, is a new technique that potentially can offer large network capacities in multi-user scenarios. With a massive MIMO system, we consider the case where a base station equipped with a large number of antenna elements simultaneously serves multiple single-antenna users in the same time-frequency resource. So far, investigatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1403.3376v3-abstract-full').style.display = 'inline'; document.getElementById('1403.3376v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1403.3376v3-abstract-full" style="display: none;"> Massive MIMO, also known as very-large MIMO or large-scale antenna systems, is a new technique that potentially can offer large network capacities in multi-user scenarios. With a massive MIMO system, we consider the case where a base station equipped with a large number of antenna elements simultaneously serves multiple single-antenna users in the same time-frequency resource. So far, investigations are mostly based on theoretical channels with independent and identically distributed (i.i.d.) complex Gaussian coefficients, i.e., i.i.d. Rayleigh channels. Here, we investigate how massive MIMO performs in channels measured in real propagation environments. Channel measurements were performed at 2.6 GHz using a virtual uniform linear array (ULA) which has a physically large aperture, and a practical uniform cylindrical array (UCA) which is more compact in size, both having 128 antenna ports. Based on measurement data, we illustrate channel behavior of massive MIMO in three representative propagation conditions, and evaluate the corresponding performance. The investigation shows that the measured channels, for both array types, allow us to achieve performance close to that in i.i.d. Rayleigh channels. It is concluded that in real propagation environments we have characteristics that can allow for efficient use of massive MIMO, i.e., the theoretical advantages of this new technology can also be harvested in real channels. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1403.3376v3-abstract-full').style.display = 'none'; document.getElementById('1403.3376v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 March, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">IEEE Transactions on Wireless Communications, 2015</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1308.2574">arXiv:1308.2574</a> <span> [<a href="https://arxiv.org/pdf/1308.2574">pdf</a>, <a href="https://arxiv.org/format/1308.2574">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> </div> <p class="title is-5 mathjax"> Line-of-Sight Obstruction Analysis for Vehicle-to-Vehicle Network Simulations in a Two-Lane Highway Scenario </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Abbas%2C+T">Taimoor Abbas</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1308.2574v2-abstract-short" style="display: inline;"> In vehicular ad-hoc networks (VANETs) the impact of vehicles as obstacles has largely been neglected in the past. Recent studies have reported that the vehicles that obstruct the line-of-sight (LOS) path may introduce 10-20 dB additional loss, and as a result reduce the communication range. Most of the traffic mobility models (TMMs) today do not treat other vehicles as obstacles and thus can not m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1308.2574v2-abstract-full').style.display = 'inline'; document.getElementById('1308.2574v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1308.2574v2-abstract-full" style="display: none;"> In vehicular ad-hoc networks (VANETs) the impact of vehicles as obstacles has largely been neglected in the past. Recent studies have reported that the vehicles that obstruct the line-of-sight (LOS) path may introduce 10-20 dB additional loss, and as a result reduce the communication range. Most of the traffic mobility models (TMMs) today do not treat other vehicles as obstacles and thus can not model the impact of LOS obstruction in VANET simulations. In this paper the LOS obstruction caused by other vehicles is studied in a highway scenario. First a car-following model is used to characterize the motion of the vehicles driving in the same direction on a two-lane highway. Vehicles are allowed to change lanes when necessary. The position of each vehicle is updated by using the car-following rules together with the lane-changing rules for the forward motion. Based on the simulated traffic a simple TMM is proposed for VANET simulations, which is capable to identify the vehicles that are in the shadow region of other vehicles. The presented traffic mobility model together with the shadow fading path loss model can take in to account the impact of LOS obstruction on the total received power in the multiple-lane highway scenarios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1308.2574v2-abstract-full').style.display = 'none'; document.getElementById('1308.2574v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 November, 2013; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 August, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 11 figures, Accepted for publication in the International Journal of Antennas and Propagation, Special Issue on Radio Wave Propagation and Wireless Channel Modeling 2013</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.3914">arXiv:1306.3914</a> <span> [<a href="https://arxiv.org/pdf/1306.3914">pdf</a>, <a href="https://arxiv.org/format/1306.3914">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TITS.2014.2349364">10.1109/TITS.2014.2349364 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time- and Frequency-Varying $K$-Factor of Non-Stationary Vehicular Channels for Safety Relevant Scenarios </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Bernad%C3%B3%2C+L">Laura Bernad贸</a>, <a href="/search/cs?searchtype=author&query=Zemen%2C+T">Thomas Zemen</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Molisch%2C+A+F">Andreas F. Molisch</a>, <a href="/search/cs?searchtype=author&query=Mecklenbr%C3%A4uker%2C+C+F">Christoph F. Mecklenbr盲uker</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.3914v3-abstract-short" style="display: inline;"> Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to fast changes in the environment. We characterize the distribution of the envelope of the first delay bin in vehicle-to-vehicle channels by means of its Rician $K$-factor. We analyze the time-frequency variability of this channel parameter using vehicular channel measurements a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.3914v3-abstract-full').style.display = 'inline'; document.getElementById('1306.3914v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.3914v3-abstract-full" style="display: none;"> Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to fast changes in the environment. We characterize the distribution of the envelope of the first delay bin in vehicle-to-vehicle channels by means of its Rician $K$-factor. We analyze the time-frequency variability of this channel parameter using vehicular channel measurements at 5.6 GHz with a bandwidth of 240 MHz for safety-relevant scenarios in intelligent transportation systems (ITS). This data enables a frequency-variability analysis from an IEEE 802.11p system point of view, which uses 10 MHz channels. We show that the small-scale fading of the envelope of the first delay bin is Ricean distributed with a varying $K$-factor. The later delay bins are Rayleigh distributed. We demonstrate that the $K$-factor cannot be assumed to be constant in time and frequency. The causes of these variations are the frequency-varying antenna radiation patterns as well as the time-varying number of active scatterers, and the effects of vegetation. We also present a simple but accurate bi-modal Gaussian mixture model, that allows to capture the $K$-factor variability in time for safety-relevant ITS scenarios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.3914v3-abstract-full').style.display = 'none'; document.getElementById('1306.3914v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 April, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, 12 figures, submitted to IEEE Transactions on Intelligent Transportation Systems for possible publication</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Intelligent Transportation Systems, vol. 16, no. 2, April 2015 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1305.3376">arXiv:1305.3376</a> <span> [<a href="https://arxiv.org/pdf/1305.3376">pdf</a>, <a href="https://arxiv.org/format/1305.3376">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/TVT.2013.2271956">10.1109/TVT.2013.2271956 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Delay and Doppler Spreads of Non-Stationary Vehicular Channels for Safety Relevant Scenarios </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Bernad%C3%B3%2C+L">Laura Bernad贸</a>, <a href="/search/cs?searchtype=author&query=Zemen%2C+T">Thomas Zemen</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Molisch%2C+A+F">Andreas F. Molisch</a>, <a href="/search/cs?searchtype=author&query=Mecklenbr%C3%A4uker%2C+C+F">Christoph F. Mecklenbr盲uker</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1305.3376v1-abstract-short" style="display: inline;"> Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to rapid changes in the environment. The non-stationary fading process can be characterized by assuming local stationarity for a region with finite extent in time and frequency. For this finite region the wide-sense stationarity and uncorrelated-scattering (WSSUS) assumption hold… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1305.3376v1-abstract-full').style.display = 'inline'; document.getElementById('1305.3376v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1305.3376v1-abstract-full" style="display: none;"> Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to rapid changes in the environment. The non-stationary fading process can be characterized by assuming local stationarity for a region with finite extent in time and frequency. For this finite region the wide-sense stationarity and uncorrelated-scattering (WSSUS) assumption holds approximately and we are able to calculate a time and frequency dependent local scattering function (LSF). In this paper, we estimate the LSF from a large set of measurements collected in the DRIVEWAY'09 measurement campaign, which focuses on scenarios for intelligent transportation systems. We then obtain the time-frequency-varying power delay profile (PDP) and the time-frequency-varying Doppler power spectral density (DSD) from the LSF. Based on the PDP and the DSD, we analyze the time-frequency-varying root mean square (RMS) delay spread and the RMS Doppler spread. We show that the distribution of these channel parameters follows a bi-modal Gaussian mixture distribution. High RMS delay spread values are observed in situations with rich scattering, while high RMS Doppler spreads are obtained in drive-by scenarios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1305.3376v1-abstract-full').style.display = 'none'; document.getElementById('1305.3376v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 May, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 5 figures, submitted to IEEE Transactions on Vehicular Communications for possible publication</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Transactions on Vehicular Technology, vol. 63, no. 1, pp. 82-93, January 2014 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1304.6690">arXiv:1304.6690</a> <span> [<a href="https://arxiv.org/pdf/1304.6690">pdf</a>, <a href="https://arxiv.org/ps/1304.6690">ps</a>, <a href="https://arxiv.org/format/1304.6690">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Information Theory">cs.IT</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/MCOM.2014.6736761">10.1109/MCOM.2014.6736761 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Massive MIMO for Next Generation Wireless Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Larsson%2C+E+G">Erik G. Larsson</a>, <a href="/search/cs?searchtype=author&query=Edfors%2C+O">Ove Edfors</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a>, <a href="/search/cs?searchtype=author&query=Marzetta%2C+T+L">Thomas L. Marzetta</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1304.6690v3-abstract-short" style="display: inline;"> Multi-user Multiple-Input Multiple-Output (MIMO) offers big advantages over conventional point-to-point MIMO: it works with cheap single-antenna terminals, a rich scattering environment is not required, and resource allocation is simplified because every active terminal utilizes all of the time-frequency bins. However, multi-user MIMO, as originally envisioned with roughly equal numbers of service… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1304.6690v3-abstract-full').style.display = 'inline'; document.getElementById('1304.6690v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1304.6690v3-abstract-full" style="display: none;"> Multi-user Multiple-Input Multiple-Output (MIMO) offers big advantages over conventional point-to-point MIMO: it works with cheap single-antenna terminals, a rich scattering environment is not required, and resource allocation is simplified because every active terminal utilizes all of the time-frequency bins. However, multi-user MIMO, as originally envisioned with roughly equal numbers of service-antennas and terminals and frequency division duplex operation, is not a scalable technology. Massive MIMO (also known as "Large-Scale Antenna Systems", "Very Large MIMO", "Hyper MIMO", "Full-Dimension MIMO" & "ARGOS") makes a clean break with current practice through the use of a large excess of service-antennas over active terminals and time division duplex operation. Extra antennas help by focusing energy into ever-smaller regions of space to bring huge improvements in throughput and radiated energy efficiency. Other benefits of massive MIMO include the extensive use of inexpensive low-power components, reduced latency, simplification of the media access control (MAC) layer, and robustness to intentional jamming. The anticipated throughput depend on the propagation environment providing asymptotically orthogonal channels to the terminals, but so far experiments have not disclosed any limitations in this regard. While massive MIMO renders many traditional research problems irrelevant, it uncovers entirely new problems that urgently need attention: the challenge of making many low-cost low-precision components that work effectively together, acquisition and synchronization for newly-joined terminals, the exploitation of extra degrees of freedom provided by the excess of service-antennas, reducing internal power consumption to achieve total energy efficiency reductions, and finding new deployment scenarios. This paper presents an overview of the massive MIMO concept and contemporary research. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1304.6690v3-abstract-full').style.display = 'none'; document.getElementById('1304.6690v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 April, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Final manuscript, to appear in IEEE Communications Magazine</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IEEE Communications Magazine, Vol. 52, No. 2, pp. 186-195, Feb. 2014 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1203.3370">arXiv:1203.3370</a> <span> [<a href="https://arxiv.org/pdf/1203.3370">pdf</a>, <a href="https://arxiv.org/format/1203.3370">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1155/2015/190607">10.1155/2015/190607 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cs?searchtype=author&query=Abbas%2C+T">Taimoor Abbas</a>, <a href="/search/cs?searchtype=author&query=Sj%C3%B6berg%2C+K">Katrin Sj枚berg</a>, <a href="/search/cs?searchtype=author&query=Karedal%2C+J">Johan Karedal</a>, <a href="/search/cs?searchtype=author&query=Tufvesson%2C+F">Fredrik Tufvesson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1203.3370v5-abstract-short" style="display: inline;"> The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, la… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1203.3370v5-abstract-full').style.display = 'inline'; document.getElementById('1203.3370v5-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1203.3370v5-abstract-full" style="display: none;"> The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, largely been neglected in most of the models, as well as in the system simulations. In this paper we present a shadow fading model targeting system simulations based on real measurements performed in urban and highway scenarios. The measurement data is separated into three categories, line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non line-of-sight due to buildings, with the help of video information recorded during the measurements. It is observed that vehicles obstructing the LOS induce an additional average attenuation of about 10 dB in the received signal power. An approach to incorporate the LOS/OLOS model into existing VANET simulators is also provided. Finally, system level VANET simulation results are presented, showing the difference between the LOS/OLOS model and a channel model based on Nakagami-m fading. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1203.3370v5-abstract-full').style.display = 'none'; document.getElementById('1203.3370v5-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 February, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 March, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2012. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 12 figures, submitted to Hindawi International Journal of Antennas and Propagation</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> Article ID 190607, 12 pages </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Tufvesson%2C+F&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" 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