CINXE.COM

<!DOCTYPE html> <html lang="en" dir="ltr"> <head>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-P63WKM1TM1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-P63WKM1TM1'); </script>  <script type="text/javascript" > (function(m,e,t,r,i,k,a){m[i]=m[i]||function(){(m[i].a=m[i].a||[]).push(arguments)}; m[i].l=1*new Date(); for (var j = 0; j < document.scripts.length; j++) {if (document.scripts[j].src === r) { return; }} k=e.createElement(t),a=e.getElementsByTagName(t)[0],k.async=1,k.src=r,a.parentNode.insertBefore(k,a)}) (window, document, "script", "https://mc.yandex.ru/metrika/tag.js", "ym"); ym(55165297, "init", { clickmap:false, trackLinks:true, accurateTrackBounce:true, webvisor:false }); </script> <noscript><div><img src="https://mc.yandex.ru/watch/55165297" style="position:absolute; left:-9999px;" alt="" /></div></noscript>    <title>Search results for: CDMA</title> <meta name="description" content="Search results for: CDMA"> <meta name="keywords" content="CDMA"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none navbar-toggler ml-auto" type="button" data-toggle="collapse" data-target="#navbarMenu" aria-controls="navbarMenu" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="w-100"> <div class="d-none d-lg-flex flex-row-reverse"> <form method="get" action="https://waset.org/search" class="form-inline my-2 my-lg-0"> <input class="form-control mr-sm-2" type="search" placeholder="Search Conferences" value="CDMA" name="q" aria-label="Search"> <button class="btn btn-light my-2 my-sm-0" type="submit"><i class="fas fa-search"></i></button> </form> </div> <div class="collapse navbar-collapse mt-1" id="navbarMenu"> <ul class="navbar-nav ml-auto align-items-center" id="mainNavMenu"> <li class="nav-item"> <a class="nav-link" href="https://waset.org/conferences" title="Conferences in 2024/2025/2026">Conferences</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/disciplines" title="Disciplines">Disciplines</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/committees" rel="nofollow">Committees</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownPublications" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Publications </a> <div class="dropdown-menu" aria-labelledby="navbarDropdownPublications"> <a class="dropdown-item" href="https://publications.waset.org/abstracts">Abstracts</a> <a class="dropdown-item" href="https://publications.waset.org">Periodicals</a> <a class="dropdown-item" href="https://publications.waset.org/archive">Archive</a> </div> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/page/support" title="Support">Support</a> </li> </ul> </div> </div> </nav> </div> </header> <main> <div class="container mt-4"> <div class="row"> <div class="col-md-9 mx-auto"> <form method="get" action="https://publications.waset.org/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="CDMA"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 62</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: CDMA</h1> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">62</span> Adaptive Subchannel Allocation for MC-CDMA System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Cuiran%20Li">Cuiran Li</a>, <a href="https://publications.waset.org/search?q=Jianli%20Xie"> Jianli Xie</a>, <a href="https://publications.waset.org/search?q=Chengshu%20Li"> Chengshu Li</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Multicarrier code-division multiple-access is one of the effective techniques to gain its multiple access capability, robustness against fading, and to mitigate the ISI. In this paper, we propose an improved mulcarrier CDMA system with adaptive subchannel allocation. We analyzed the performance of our proposed system in frequency selective fading environment with narrowband interference existing and compared it with that of parallel transmission over many subchannels (namely, conventional MC-CDMA scheme) and DS-CDMA system. Simulation results show that adaptive subchannel allocation scheme, when used in conventional multicarrier CDMA system, the performance will be greatly improved. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=MC-CDMA" title="MC-CDMA">MC-CDMA</a>, <a href="https://publications.waset.org/search?q=Rayleigh%20fading" title=" Rayleigh fading"> Rayleigh fading</a>, <a href="https://publications.waset.org/search?q=Narrowbandinterference" title=" Narrowbandinterference"> Narrowbandinterference</a>, <a href="https://publications.waset.org/search?q=Channel%20estimation." title=" Channel estimation."> Channel estimation.</a> </p> <a href="https://publications.waset.org/2868/adaptive-subchannel-allocation-for-mc-cdma-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/2868/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/2868/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/2868/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/2868/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/2868/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/2868/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/2868/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/2868/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/2868/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/2868/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/2868.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1573</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">61</span> Effect of Iterative Algorithm on the Performance of MC-CDMA System with Nonlinear Models of HPA</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=R.%20Blicha">R. Blicha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>High Peak to Average Power Ratio (PAPR) of the transmitted signal is a serious problem in multicarrier systems (MC), such as Orthogonal Frequency Division Multiplexing (OFDM), or in Multi-Carrier Code Division Multiple Access (MC-CDMA) systems, due to large number of subcarriers. This effect is possible reduce with some PAPR reduction techniques. Spreading sequences at the presence of Saleh and Rapp models of high power amplifier (HPA) have big influence on the behavior of system. In this paper we investigate the bit-error-rate (BER) performance of MC-CDMA systems. Basically we can see from simulations that the MC-CDMA system with Iterative algorithm can be providing significantly better results than the MC-CDMA system. The results of our analyses are verified via simulation.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=MC-CDMA" title="MC-CDMA">MC-CDMA</a>, <a href="https://publications.waset.org/search?q=Iterative%20algorithm" title=" Iterative algorithm"> Iterative algorithm</a>, <a href="https://publications.waset.org/search?q=PAPR" title=" PAPR"> PAPR</a>, <a href="https://publications.waset.org/search?q=BER" title=" BER"> BER</a>, <a href="https://publications.waset.org/search?q=Saleh" title=" Saleh"> Saleh</a>, <a href="https://publications.waset.org/search?q=Rapp" title=" Rapp"> Rapp</a>, <a href="https://publications.waset.org/search?q=Spreading%20Sequences." title=" Spreading Sequences."> Spreading Sequences.</a> </p> <a href="https://publications.waset.org/10000520/effect-of-iterative-algorithm-on-the-performance-of-mc-cdma-system-with-nonlinear-models-of-hpa" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/10000520/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/10000520/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/10000520/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/10000520/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/10000520/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/10000520/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/10000520/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/10000520/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/10000520/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/10000520/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/10000520.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2378</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">60</span> Performance Analysis of QS-CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Cuiran%20Li">Cuiran Li</a>, <a href="https://publications.waset.org/search?q=Jianli%20Xie"> Jianli Xie</a>, <a href="https://publications.waset.org/search?q=Chengshu%20Li"> Chengshu Li</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the paper, the performance of quasi-synchronous CDMA (QS-CDMA) system, which can allow an increased timing error in synchronized access, is discussed. Average BER performance of the system is analyzed in the condition of different access timing error and different asynchronous users by simulation in AWGN channel. The results show that QS-CDMA system is shown to have great performance gain over the asynchronous system when access timing error is within a few chips and asynchronous users is tolerable. However, with access timing error increasing and asynchronous users increasing, the performance of QS-CDMA will degrade. Also, we can determine the number of tolerable asynchronous users for different access timing error by simulation figures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Code-division%20multiple%20access" title="Code-division multiple access">Code-division multiple access</a>, <a href="https://publications.waset.org/search?q=Quasi-SynchronousCDMA" title=" Quasi-SynchronousCDMA"> Quasi-SynchronousCDMA</a>, <a href="https://publications.waset.org/search?q=Access%20timing%20error" title=" Access timing error"> Access timing error</a> </p> <a href="https://publications.waset.org/5250/performance-analysis-of-qs-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/5250/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/5250/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/5250/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/5250/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/5250/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/5250/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/5250/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/5250/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/5250/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/5250/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/5250.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1311</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">59</span> A Fast Code Acquisition Scheme for O-CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Youngpo%20Lee">Youngpo Lee</a>, <a href="https://publications.waset.org/search?q=Jaewoo%20Lee"> Jaewoo Lee</a>, <a href="https://publications.waset.org/search?q=Seokho%20Yoon"> Seokho Yoon</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper proposes a fast code acquisition scheme for optical code division multiple access (O-CDMA) systems. Unlike the conventional scheme, the proposed scheme employs multiple thresholds providing a shorter mean acquisition time (MAT) performance. The simulation results show that the MAT of the proposed scheme is shorter than that of the conventional scheme. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Optical%20CDMA" title="Optical CDMA">Optical CDMA</a>, <a href="https://publications.waset.org/search?q=acquisition" title=" acquisition"> acquisition</a>, <a href="https://publications.waset.org/search?q=MAT" title=" MAT"> MAT</a>, <a href="https://publications.waset.org/search?q=multiple-shift" title=" multiple-shift"> multiple-shift</a> </p> <a href="https://publications.waset.org/455/a-fast-code-acquisition-scheme-for-o-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/455/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/455/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/455/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/455/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/455/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/455/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/455/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/455/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/455/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/455/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/455.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1955</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">58</span> Blind Identification Channel Using Higher Order Cumulants with Application to Equalization for MC鈭扖DMA System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Mohammed%20Zidane">Mohammed Zidane</a>, <a href="https://publications.waset.org/search?q=Said%20Safi"> Said Safi</a>, <a href="https://publications.waset.org/search?q=Mohamed%20Sabri"> Mohamed Sabri</a>, <a href="https://publications.waset.org/search?q=Ahmed%20Boumezzough"> Ahmed Boumezzough</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper we propose an algorithm based on higher order cumulants, for blind impulse response identification of frequency radio channels and downlink (MC−CDMA) system Equalization. In order to test its efficiency, we have compared with another algorithm proposed in the literature, for that we considered on theoretical channel as the Proakis’s ‘B’ channel and practical frequency selective fading channel, called Broadband Radio Access Network (BRAN C), normalized for (MC−CDMA) systems, excited by non-Gaussian sequences. In the part of (MC−CDMA), we use the Minimum Mean Square Error (MMSE) equalizer after the channel identification to correct the channel’s distortion. The simulation results, in noisy environment and for different signal to noise ratio (SNR), are presented to illustrate the accuracy of the proposed algorithm.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Blind%20identification%20and%20equalization" title="Blind identification and equalization">Blind identification and equalization</a>, <a href="https://publications.waset.org/search?q=Higher%20Order%0D%0ACumulants" title=" Higher Order Cumulants"> Higher Order Cumulants</a>, <a href="https://publications.waset.org/search?q=%28MC%E2%88%92CDMA%29%20system" title=" (MC鈭扖DMA) system"> (MC鈭扖DMA) system</a>, <a href="https://publications.waset.org/search?q=MMSE%20equalizer." title=" MMSE equalizer."> MMSE equalizer.</a> </p> <a href="https://publications.waset.org/9997867/blind-identification-channel-using-higher-order-cumulants-with-application-to-equalization-for-mccdma-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/9997867/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/9997867/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/9997867/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/9997867/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/9997867/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/9997867/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/9997867/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/9997867/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/9997867/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/9997867/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/9997867.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1781</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">57</span> The Performance of Genetic Algorithm for Synchronized Chaotic Chen System in CDMA Satellite Channel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Salah%20Salmi">Salah Salmi</a>, <a href="https://publications.waset.org/search?q=Karim%20Kemih"> Karim Kemih</a>, <a href="https://publications.waset.org/search?q=Malek%20Benslama"> Malek Benslama</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Synchronization is a difficult problem in CDMA satellite communications. Due to the influence of additive noise and fading in the mobile channel, it is not easy to keep up with the attenuation and offset. This paper considers a recently proposed approach to solve the problem of synchronization chaotic Chen system in CDMA satellite communication in the presence of constant attenuation and offset. An analytic algorithm that provides closed form channel and carrier offset estimates is presented. The principle of this approach is based on adding a compensation block before the receiver to compensate the distortion of the imperfect channel by using genetic algorithm. The resultants presented, show that the receiver is able to recover rapidly the synchronization with the transmitter. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Chaotic%20Chen%20system" title="Chaotic Chen system">Chaotic Chen system</a>, <a href="https://publications.waset.org/search?q=genetic%20algorithm" title=" genetic algorithm"> genetic algorithm</a>, <a href="https://publications.waset.org/search?q=Synchronization" title=" Synchronization"> Synchronization</a>, <a href="https://publications.waset.org/search?q=CDMA" title=" CDMA"> CDMA</a> </p> <a href="https://publications.waset.org/2196/the-performance-of-genetic-algorithm-for-synchronized-chaotic-chen-system-in-cdma-satellite-channel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/2196/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/2196/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/2196/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/2196/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/2196/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/2196/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/2196/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/2196/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/2196/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/2196/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/2196.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1535</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">56</span> Design and Performance of Adaptive Polarized MIMO MC-SS-CDMA System for Downlink Mobile Communications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Joseph%20V.%20M.%20Halim">Joseph V. M. Halim</a>, <a href="https://publications.waset.org/search?q=Hesham%20El-Badawy"> Hesham El-Badawy</a>, <a href="https://publications.waset.org/search?q=Hadia%20M.%20El-Hennawy"> Hadia M. El-Hennawy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, an adaptive polarized Multiple-Input Multiple-Output (MIMO) Multicarrier Spread Spectrum Code Division Multiple Access (MC-SS-CDMA) system is designed for downlink mobile communications. The proposed system will be examined in Frequency Division Duplex (FDD) mode for both macro urban and suburban environments. For the same transmission bandwidth, a performance comparison between both nonoverlapped and orthogonal Frequency Division Multiplexing (FDM) schemes will be presented. Also, the proposed system will be compared with both the closed loop vertical MIMO MC-SS-CDMA system and the synchronous vertical STBC-MIMO MC-SS-CDMA system. As will be shown, the proposed system introduces a significant performance gain as well as reducing the spatial dimensions of the MIMO system and simplifying the receiver implementation. The effect of the polarization diversity characteristics on the BER performance will be discussed. Also, the impact of excluding the cross-polarization MCSS- CDMA blocks in the base station will be investigated. In addition, the system performance will be evaluated under different Feedback Information (FBI) rates for slowly-varying channels. Finally, a performance comparison for vehicular and pedestrian environments will be presented <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Closed%20loop%20technique" title="Closed loop technique">Closed loop technique</a>, <a href="https://publications.waset.org/search?q=MC-SS-CDMA" title=" MC-SS-CDMA"> MC-SS-CDMA</a>, <a href="https://publications.waset.org/search?q=Polarized%20MIMO%20systems" title=" Polarized MIMO systems"> Polarized MIMO systems</a>, <a href="https://publications.waset.org/search?q=Transmit%20diversity." title=" Transmit diversity."> Transmit diversity.</a> </p> <a href="https://publications.waset.org/15143/design-and-performance-of-adaptive-polarized-mimo-mc-ss-cdma-system-for-downlink-mobile-communications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/15143/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/15143/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/15143/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/15143/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/15143/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/15143/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/15143/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/15143/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/15143/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/15143/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/15143.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1622</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">55</span> Application of ESA in the CAVE Mode Authentication</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Keonwoo%20Kim">Keonwoo Kim</a>, <a href="https://publications.waset.org/search?q=Dowon%20Hong"> Dowon Hong</a>, <a href="https://publications.waset.org/search?q=Kyoil%20Chung"> Kyoil Chung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper proposes the authentication method using ESA algorithm instead of using CAVE algorithm in the CDMA mobile communication systems including IS-95 and CDMA2000 1x. And, we analyze to apply ESA mechanism on behalf of CAVE mechanism without the change of message format and air interface in the existing CDMA systems. If ESA algorithm can be used as the substitution of CAVE algorithm, security strength of authentication algorithm is intensified without protocol change. An algorithm replacement proposed in this paper is not to change an authentication mechanism, but to configure input of ESA algorithm and to produce output. Therefore, our proposal can be the compatible to the existing systems. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=ESA" title="ESA">ESA</a>, <a href="https://publications.waset.org/search?q=CAVE" title=" CAVE"> CAVE</a>, <a href="https://publications.waset.org/search?q=CDMA" title=" CDMA"> CDMA</a>, <a href="https://publications.waset.org/search?q=authentication" title=" authentication"> authentication</a>, <a href="https://publications.waset.org/search?q=mobilecommunication." title=" mobilecommunication."> mobilecommunication.</a> </p> <a href="https://publications.waset.org/3251/application-of-esa-in-the-cave-mode-authentication" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/3251/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/3251/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/3251/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/3251/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/3251/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/3251/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/3251/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/3251/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/3251/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/3251/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/3251.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1592</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">54</span> A SAW-less Dual-Band CDMA Diversity and Simultaneous-GPS Zero-IF Receiver</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Bassem%20Fahs">Bassem Fahs</a>, <a href="https://publications.waset.org/search?q=Philippe%20Barr%C3%A9"> Philippe Barr茅</a>, <a href="https://publications.waset.org/search?q=Patrick%20Ozenne"> Patrick Ozenne</a>, <a href="https://publications.waset.org/search?q=Eric%20Chartier"> Eric Chartier</a>, <a href="https://publications.waset.org/search?q=Guillaume%20H%C3%A9rault"> Guillaume H茅rault</a>, <a href="https://publications.waset.org/search?q=S%C3%A9bastien%20Jacquet"> S茅bastien Jacquet</a>, <a href="https://publications.waset.org/search?q=S%C3%A9bastien%20Clamagirand"> S茅bastien Clamagirand</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We present a dual-band (Cellular & PCS) dual-path zero-IF receiver for CDMA2000 diversity, monitoring and simultaneous-GPS. The secondary path is a SAW-less diversity CDMA receiver which can be also used for advanced features like monitoring when supported with an additional external VCO. A GPS receiver is integrated with its dedicated VCO allowing simultaneous positioning during a cellular call. The circuit is implemented in a 0.25渭m 40GHz-fT BiCMOS process and uses a HVQFN 56-pin package. It consumes a maximum 300mW from a 2.8V supply in dual-modes. The chip area is 12.8mm2. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=CDMA" title="CDMA">CDMA</a>, <a href="https://publications.waset.org/search?q=diversity" title=" diversity"> diversity</a>, <a href="https://publications.waset.org/search?q=GPS" title=" GPS"> GPS</a>, <a href="https://publications.waset.org/search?q=zero-IF" title=" zero-IF"> zero-IF</a>, <a href="https://publications.waset.org/search?q=SAW-less" title=" SAW-less"> SAW-less</a> </p> <a href="https://publications.waset.org/13335/a-saw-less-dual-band-cdma-diversity-and-simultaneous-gps-zero-if-receiver" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/13335/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/13335/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/13335/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/13335/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/13335/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/13335/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/13335/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/13335/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/13335/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/13335/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/13335.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1816</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">53</span> Performance of Chaotic Lu System in CDMA Satellites Communications Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=K.%20Kemih">K. Kemih</a>, <a href="https://publications.waset.org/search?q=M.%20Benslama"> M. Benslama</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper investigates the problem of spreading sequence and receiver code synchronization techniques for satellite based CDMA communications systems. The performance of CDMA system depends on the autocorrelation and cross-correlation properties of the used spreading sequences. In this paper we propose the uses of chaotic Lu system to generate binary sequences for spreading codes in a direct sequence spread CDMA system. To minimize multiple access interference (MAI) we propose the use of genetic algorithm for optimum selection of chaotic spreading sequences. To solve the problem of transmitter-receiver synchronization, we use the passivity controls. The concept of semipassivity is defined to find simple conditions which ensure boundedness of the solutions of coupled Lu systems. Numerical results are presented to show the effectiveness of the proposed approach. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=About%20Chaotic%20Lu%20system" title="About Chaotic Lu system">About Chaotic Lu system</a>, <a href="https://publications.waset.org/search?q=synchronization" title=" synchronization"> synchronization</a>, <a href="https://publications.waset.org/search?q=Spreading%20sequence" title="Spreading sequence">Spreading sequence</a>, <a href="https://publications.waset.org/search?q=Genetic%20Algorithm.%20Passive%20System" title=" Genetic Algorithm. Passive System"> Genetic Algorithm. Passive System</a> </p> <a href="https://publications.waset.org/14992/performance-of-chaotic-lu-system-in-cdma-satellites-communications-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/14992/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/14992/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/14992/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/14992/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/14992/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/14992/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/14992/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/14992/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/14992/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/14992/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/14992.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1747</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">52</span> Blind Channel Estimation Based on URV Decomposition Technique for Uplink of MC-CDMA</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Pradya%20Pornnimitkul">Pradya Pornnimitkul</a>, <a href="https://publications.waset.org/search?q=Suwich%20Kunaruttanapruk"> Suwich Kunaruttanapruk</a>, <a href="https://publications.waset.org/search?q=Bamrung%20Tau%20Sieskul"> Bamrung Tau Sieskul</a>, <a href="https://publications.waset.org/search?q=Somchai%20Jitapunkul"> Somchai Jitapunkul</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper, we investigate a blind channel estimation method for Multi-carrier CDMA systems that use a subspace decomposition technique. This technique exploits the orthogonality property between the noise subspace and the received user codes to obtain channel of each user. In the past we used Singular Value Decomposition (SVD) technique but SVD have most computational complexity so in this paper use a new algorithm called URV Decomposition, which serve as an intermediary between the QR decomposition and SVD, replaced in SVD technique to track the noise space of the received data. Because of the URV decomposition has almost the same estimation performance as the SVD, but has less computational complexity.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Channel%20estimation" title="Channel estimation">Channel estimation</a>, <a href="https://publications.waset.org/search?q=MC-CDMA" title=" MC-CDMA"> MC-CDMA</a>, <a href="https://publications.waset.org/search?q=SVD" title=" SVD"> SVD</a>, <a href="https://publications.waset.org/search?q=URV." title=" URV."> URV.</a> </p> <a href="https://publications.waset.org/14167/blind-channel-estimation-based-on-urv-decomposition-technique-for-uplink-of-mc-cdma" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/14167/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/14167/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/14167/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/14167/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/14167/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/14167/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/14167/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/14167/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/14167/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/14167/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/14167.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1780</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">51</span> Adaptive Equalization Using Controlled Equal Gain Combining for Uplink/Downlink MC-CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Miloud%20Frikel">Miloud Frikel </a>, <a href="https://publications.waset.org/search?q=Boubekeur%20Targui"> Boubekeur Targui</a>, <a href="https://publications.waset.org/search?q=Francois%20Hamon"> Francois Hamon</a>, <a href="https://publications.waset.org/search?q=Mohammed%20M%27SAAD"> Mohammed M'SAAD</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper we propose an enhanced equalization technique for multi-carrier code division multiple access (MC-CDMA). This method is based on the control of Equal Gain Combining (EGC) technique. Indeed, we introduce a new level changer to the EGC equalizer in order to adapt the equalization parameters to the channel coefficients. The optimal equalization level is, first, determined by channel training. The new approach reduces drastically the mutliuser interferences caused by interferes, without increasing the noise power. To compare the performances of the proposed equalizer, the theoretical analysis and numerical performances are given.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=MC-CDMA" title="MC-CDMA">MC-CDMA</a>, <a href="https://publications.waset.org/search?q=Equalization" title=" Equalization"> Equalization</a>, <a href="https://publications.waset.org/search?q=EGC" title=" EGC"> EGC</a>, <a href="https://publications.waset.org/search?q=Single%20User%20Detection." title=" Single User Detection."> Single User Detection.</a> </p> <a href="https://publications.waset.org/6126/adaptive-equalization-using-controlled-equal-gain-combining-for-uplinkdownlink-mc-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/6126/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/6126/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/6126/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/6126/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/6126/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/6126/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/6126/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/6126/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/6126/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/6126/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/6126.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1408</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">50</span> WDM and OCDMA Systems under MAI Effects: A Comparison Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Hilal%20A.%20Fadhil">Hilal A. Fadhil</a>, <a href="https://publications.waset.org/search?q=Thanaa%20Hussein%20Abd"> Thanaa Hussein Abd</a>, <a href="https://publications.waset.org/search?q=Hamza%20M.%20R.%20Al-Khafaji"> Hamza M. R. Al-Khafaji</a>, <a href="https://publications.waset.org/search?q=S.%20A.%20Aljunid"> S. A. Aljunid</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents a comparison between Spectrum- Sliced Wavelength Division Multiplexing (SS-WDM) and Spectrum Amplitude Coding Optical Code Division Multiple Access (SAC Optical CDMA) systems for different light sources. The performance of the system is shown in the simulated results of the bit error rate (BER) and the eye diagram of both systems. The comparison results indicate that the Multiple Access Interference (MAI) effects have a significant impact on SS-WDM over SAC Optical CDMA systems. Finally, in terms of spectral efficiency at constant BER of 10-12, SSWDM offers higher spectral efficiency than optical CDMA since no bandwidth expansion in needed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=WDM" title="WDM">WDM</a>, <a href="https://publications.waset.org/search?q=OCDMA" title=" OCDMA"> OCDMA</a>, <a href="https://publications.waset.org/search?q=BER" title=" BER"> BER</a>, <a href="https://publications.waset.org/search?q=RD%20code" title=" RD code"> RD code</a> </p> <a href="https://publications.waset.org/14704/wdm-and-ocdma-systems-under-mai-effects-a-comparison-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/14704/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/14704/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/14704/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/14704/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/14704/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/14704/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/14704/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/14704/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/14704/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/14704/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/14704.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2381</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">49</span> Capacity of Overloaded DS-CDMA System on Rayleigh Fading Channel with Timing Error</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Preetam%20Kumar">Preetam Kumar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The number of users supported in a DS-CDMA cellular system is typically less than spreading factor (N), and the system is said to be underloaded. Overloading is a technique to accommodate more number of users than the spreading factor N. In O/O overloading scheme, the first set is assigned to the N synchronous users and the second set is assigned to the additional synchronous users. An iterative multistage soft decision interference cancellation (SDIC) receiver is used to remove high level of interference between the two sets. Performance is evaluated in terms of the maximum number acceptable users so that the system performance is degraded slightly compared to the single user performance at a specified BER. In this paper, the capacity of CDMA based O/O overloading scheme is evaluated with SDIC receiver. It is observed that O/O scheme using orthogonal Gold codes provides 25% channel overloading (N=64) for synchronous DS-CDMA system on an AWGN channel in the uplink at a BER of 1e-5.For a Rayleigh faded channel, the critical capacity is 40% at a BER of 5e-5 assuming synchronous users. But in practical systems, perfect chip timing is very difficult to maintain in the uplink.. We have shown that the overloading performance reduces to 11% for a timing synchronization error of 0.02Tc for a BER of 1e-5. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=DS-CDMA" title="DS-CDMA">DS-CDMA</a>, <a href="https://publications.waset.org/search?q=Interference%20Cancellation" title=" Interference Cancellation"> Interference Cancellation</a>, <a href="https://publications.waset.org/search?q=MultiuserDetection" title=" MultiuserDetection"> MultiuserDetection</a>, <a href="https://publications.waset.org/search?q=Orthogonal%20codes" title=" Orthogonal codes"> Orthogonal codes</a>, <a href="https://publications.waset.org/search?q=Overloading." title=" Overloading."> Overloading.</a> </p> <a href="https://publications.waset.org/14359/capacity-of-overloaded-ds-cdma-system-on-rayleigh-fading-channel-with-timing-error" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/14359/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/14359/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/14359/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/14359/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/14359/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/14359/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/14359/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/14359/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/14359/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/14359/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/14359.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1717</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">48</span> Joint Microstatistic Multiuser Detection and Cancellation of Nonlinear Distortion Effects for the Uplink of MC-CDMA Systems Using Golay Codes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Peter%20Drotar">Peter Drotar</a>, <a href="https://publications.waset.org/search?q=Juraj%20Gazda"> Juraj Gazda</a>, <a href="https://publications.waset.org/search?q=Pavol%20Galajda"> Pavol Galajda</a>, <a href="https://publications.waset.org/search?q=Dusan%20Kocur"> Dusan Kocur</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The study in this paper underlines the importance of correct joint selection of the spreading codes for uplink of multicarrier code division multiple access (MC-CDMA) at the transmitter side and detector at the receiver side in the presence of nonlinear distortion due to high power amplifier (HPA). The bit error rate (BER) of system for different spreading sequences (Walsh code, Gold code, orthogonal Gold code, Golay code and Zadoff-Chu code) and different kinds of receivers (minimum mean-square error receiver (MMSE-MUD) and microstatistic multi-user receiver (MSF-MUD)) is compared by means of simulations for MC-CDMA transmission system. Finally, the results of analysis will show, that the application of MSF-MUD in combination with Golay codes can outperform significantly the other tested spreading codes and receivers for all mostly used models of HPA. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=HPA" title="HPA">HPA</a>, <a href="https://publications.waset.org/search?q=MC-CDMA" title=" MC-CDMA"> MC-CDMA</a>, <a href="https://publications.waset.org/search?q=microstatistic%20filter" title=" microstatistic filter"> microstatistic filter</a>, <a href="https://publications.waset.org/search?q=multi-user%20receivers" title=" multi-user receivers"> multi-user receivers</a>, <a href="https://publications.waset.org/search?q=PAPR." title="PAPR.">PAPR.</a> </p> <a href="https://publications.waset.org/709/joint-microstatistic-multiuser-detection-and-cancellation-of-nonlinear-distortion-effects-for-the-uplink-of-mc-cdma-systems-using-golay-codes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/709/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/709/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/709/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/709/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/709/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/709/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/709/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/709/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/709/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/709/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/709.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1761</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">47</span> Analysis of MAC Protocols with Correlation Receiver for OCDMA Networks - Part II</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Shivaleela%20E.%20S.">Shivaleela E. S.</a>, <a href="https://publications.waset.org/search?q=Shrikant%20S.%20Tangade"> Shrikant S. Tangade</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper optical code-division multiple-access (OCDMA) packet network is considered, which offers inherent security in the access networks. Two types of random access protocols are proposed for packet transmission. In protocol 1, all distinct codes and in protocol 2, distinct codes as well as shifted versions of all these codes are used. O-CDMA network performance using optical orthogonal codes (OOCs) 1-D and two-dimensional (2-D) wavelength/time single-pulse-per-row (W/T SPR) codes are analyzed. The main advantage of using 2-D codes instead of onedimensional (1-D) codes is to reduce the errors due to multiple access interference among different users. In this paper, correlation receiver is considered in the analysis. Using analytical model, we compute and compare packet-success probability for 1-D and 2-D codes in an O-CDMA network and the analysis shows improved performance with 2-D codes as compared to 1-D codes.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Optical%20code-division%20multiple-access" title="Optical code-division multiple-access">Optical code-division multiple-access</a>, <a href="https://publications.waset.org/search?q=optical%20CDMA%20correlation%20receiver" title=" optical CDMA correlation receiver"> optical CDMA correlation receiver</a>, <a href="https://publications.waset.org/search?q=wavelength%2Ftime%20optical%20CDMA%20codes." title=" wavelength/time optical CDMA codes."> wavelength/time optical CDMA codes.</a> </p> <a href="https://publications.waset.org/5938/analysis-of-mac-protocols-with-correlation-receiver-for-ocdma-networks-part-ii" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/5938/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/5938/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/5938/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/5938/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/5938/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/5938/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/5938/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/5938/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/5938/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/5938/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/5938.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1394</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">46</span> A PN Sequence Generator based on Residue Arithmetic for Multi-User DS-CDMA Applications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Chithra%20R">Chithra R</a>, <a href="https://publications.waset.org/search?q=Pallab%20Maji"> Pallab Maji</a>, <a href="https://publications.waset.org/search?q=Sarat%20Kumar%20Patra"> Sarat Kumar Patra</a>, <a href="https://publications.waset.org/search?q=Girija%20Sankar%20Rath"> Girija Sankar Rath</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The successful use of CDMA technology is based on the construction of large families of encoding sequences with good correlation properties. This paper discusses PN sequence generation based on Residue Arithmetic with an effort to improve the performance of existing interference-limited CDMA technology for mobile cellular systems. All spreading codes with residual number system proposed earlier did not consider external interferences, multipath propagation, Doppler effect etc. In literature the use of residual arithmetic in DS-CDMA was restricted to encoding of already spread sequence; where spreading of sequence is done by some existing techniques. The novelty of this paper is the use of residual number system in generation of the PN sequences which is used to spread the message signal. The significance of cross-correlation factor in alleviating multi-access interference is also discussed. The RNS based PN sequence has superior performance than most of the existing codes that are widely used in DS-CDMA applications. Simulation results suggest that the performance of the proposed system is superior to many existing systems. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Direct-Sequence%20Code%20Division%20Multiple%20Access%20%28DSCDMA%29" title="Direct-Sequence Code Division Multiple Access (DSCDMA)">Direct-Sequence Code Division Multiple Access (DSCDMA)</a>, <a href="https://publications.waset.org/search?q=Multiple-Access%20Interference%20%28MAI%29" title=" Multiple-Access Interference (MAI)"> Multiple-Access Interference (MAI)</a>, <a href="https://publications.waset.org/search?q=PN%20Sequence" title=" PN Sequence"> PN Sequence</a>, <a href="https://publications.waset.org/search?q=Residue%0ANumber%20System%20%28RNS%29." title=" Residue Number System (RNS)."> Residue Number System (RNS).</a> </p> <a href="https://publications.waset.org/4547/a-pn-sequence-generator-based-on-residue-arithmetic-for-multi-user-ds-cdma-applications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/4547/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/4547/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/4547/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/4547/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/4547/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/4547/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/4547/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/4547/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/4547/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/4547/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/4547.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2436</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">45</span> Performance Analysis of IDMA Scheme Using Quasi-Cyclic Low Density Parity Check Codes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Anurag%20Saxena">Anurag Saxena</a>, <a href="https://publications.waset.org/search?q=Alkesh%20Agrawal"> Alkesh Agrawal</a>, <a href="https://publications.waset.org/search?q=Dinesh%20Kumar"> Dinesh Kumar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>The next generation mobile communication systems i.e. fourth generation (4G) was developed to accommodate the quality of service and required data rate. This project focuses on multiple access technique proposed in 4G communication systems. It is attempted to demonstrate the IDMA (Interleave Division Multiple Access) technology. The basic principle of IDMA is that interleaver is different for each user whereas CDMA employs different signatures. IDMA inherits many advantages of CDMA such as robust against fading, easy cell planning; dynamic channel sharing and IDMA increase the spectral efficiency and reduce the receiver complexity. In this, performance of IDMA is analyzed using QC-LDPC coding scheme further it is compared with LDPC coding and at last BER is calculated and plotted in MATLAB.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=4G" title="4G">4G</a>, <a href="https://publications.waset.org/search?q=QC-LDPC" title=" QC-LDPC"> QC-LDPC</a>, <a href="https://publications.waset.org/search?q=CDMA" title=" CDMA"> CDMA</a>, <a href="https://publications.waset.org/search?q=IDMA." title=" IDMA."> IDMA.</a> </p> <a href="https://publications.waset.org/10004401/performance-analysis-of-idma-scheme-using-quasi-cyclic-low-density-parity-check-codes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/10004401/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/10004401/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/10004401/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/10004401/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/10004401/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/10004401/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/10004401/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/10004401/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/10004401/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/10004401/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/10004401.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1988</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">44</span> MMSE Based Beamforming for Chip Interleaved CDMA in Aeronautical Mobile Radio Channel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Sherif%20K.%20El%20Dyasti">Sherif K. El Dyasti</a>, <a href="https://publications.waset.org/search?q=Esam%20A.%20Hagras"> Esam A. Hagras</a>, <a href="https://publications.waset.org/search?q=Adel%20E.%20El-Hennawy"> Adel E. El-Hennawy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>This paper addresses the performance of antenna array beamforming on Chip-Interleaved Code Division Multiple Access (CI_CDMA) system based on Minimum Mean Square Error (MMSE) detector in aeronautical mobile radio channel. Multipath fading, Doppler shifts caused by the speed of the aircraft, and Multiple Access Interference (MAI) are the most important reasons that affect and reduce the performance of aeronautical system. In this paper we suggested the CI-CDMA with antenna array to combat this fading and improve the bit error rate (BER) performance. We further evaluate the performance of the proposed system in the four standard scenarios in aeronautical mobile radio channel.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Aeronautical%20Channel" title="Aeronautical Channel">Aeronautical Channel</a>, <a href="https://publications.waset.org/search?q=CI-CDMA" title=" CI-CDMA"> CI-CDMA</a>, <a href="https://publications.waset.org/search?q=Beamforming." title=" Beamforming."> Beamforming.</a> </p> <a href="https://publications.waset.org/9997293/mmse-based-beamforming-for-chip-interleaved-cdma-in-aeronautical-mobile-radio-channel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/9997293/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/9997293/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/9997293/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/9997293/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/9997293/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/9997293/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/9997293/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/9997293/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/9997293/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/9997293/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/9997293.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2144</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">43</span> An Investigation on Efficient Spreading Codes for Transmitter Based Techniques to Mitigate MAI and ISI in TDD/CDMA Downlink</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Abhijit%20Mitra">Abhijit Mitra</a>, <a href="https://publications.waset.org/search?q=C.%20Ardil"> C. Ardil</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>We investigate efficient spreading codes for transmitter based techniques of code division multiple access (CDMA) systems. The channel is considered to be known at the transmitter which is usual in a time division duplex (TDD) system where the channel is assumed to be the same on uplink and downlink. For such a TDD/CDMA system, both bitwise and blockwise multiuser transmission schemes are taken up where complexity is transferred to the transmitter side so that the receiver has minimum complexity. Different spreading codes are considered at the transmitter to spread the signal efficiently over the entire spectrum. The bit error rate (BER) curves portray the efficiency of the codes in presence of multiple access interference (MAI) as well as inter symbol interference (ISI).</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Code%20division%20multiple%20access" title="Code division multiple access">Code division multiple access</a>, <a href="https://publications.waset.org/search?q=time%20division%20duplex" title=" time division duplex"> time division duplex</a>, <a href="https://publications.waset.org/search?q=transmitter%20technique" title="transmitter technique">transmitter technique</a>, <a href="https://publications.waset.org/search?q=precoding" title=" precoding"> precoding</a>, <a href="https://publications.waset.org/search?q=pre-rake" title=" pre-rake"> pre-rake</a>, <a href="https://publications.waset.org/search?q=rake" title=" rake"> rake</a>, <a href="https://publications.waset.org/search?q=spreading%20code." title=" spreading code."> spreading code.</a> </p> <a href="https://publications.waset.org/10076/an-investigation-on-efficient-spreading-codes-for-transmitter-based-techniques-to-mitigate-mai-and-isi-in-tddcdma-downlink" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/10076/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/10076/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/10076/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/10076/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/10076/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/10076/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/10076/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/10076/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/10076/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/10076/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/10076.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1474</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">42</span> Semi-Blind Two-Dimensional Code Acquisition in CDMA Communications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Rui%20Wu">Rui Wu</a>, <a href="https://publications.waset.org/search?q=Tapani%20Ristaniemi"> Tapani Ristaniemi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper, we propose a new algorithm for joint time-delay and direction-of-arrival (DOA) estimation, here called two-dimensional code acquisition, in an asynchronous directsequence code-division multiple-access (DS-CDMA) array system. This algorithm depends on eigenvector-eigenvalue decomposition of sample correlation matrix, and requires to know desired user-s training sequence. The performance of the algorithm is analyzed both analytically and numerically in uncorrelated and coherent multipath environment. Numerical examples show that the algorithm is robust with unknown number of coherent signals.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Two-Dimensional%20Code%20Acquisition" title="Two-Dimensional Code Acquisition">Two-Dimensional Code Acquisition</a>, <a href="https://publications.waset.org/search?q=EV-t" title=" EV-t"> EV-t</a>, <a href="https://publications.waset.org/search?q=DSCDMA" title=" DSCDMA"> DSCDMA</a> </p> <a href="https://publications.waset.org/2408/semi-blind-two-dimensional-code-acquisition-in-cdma-communications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/2408/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/2408/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/2408/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/2408/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/2408/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/2408/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/2408/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/2408/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/2408/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/2408/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/2408.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1526</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">41</span> Multihop Cooperative Transmissions for Asymmetric Traffic Accommodation in CDMA/FDD Cellular Networks</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Kazuo%20Mori">Kazuo Mori</a>, <a href="https://publications.waset.org/search?q=Takeo%20Saga"> Takeo Saga</a>, <a href="https://publications.waset.org/search?q=Katsuhiro%20Naito"> Katsuhiro Naito</a>, <a href="https://publications.waset.org/search?q=Hideo%20Kobayashi"> Hideo Kobayashi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The asymmetric trafc between uplink and downlink over recent mobile communication systems has been conspicuous because of providing new communication services. This paper proposes an asymmetric trafc accommodation scheme adopting a multihop cooperative transmission technique for CDMA/FDD cellular networks. The proposed scheme employs the cooperative transmission technique in the already proposed downlink multihop transmissions for the accommodation of the asymmetric trafc, which utilizes the vacant uplink band for the downlink relay transmissions. The proposed scheme reduces the transmission power at the downlink relay transmissions and then suppresses the interference to the uplink communications, and thus, improves the uplink performance. The proposed scheme is evaluated by computer simulation and the results show that it can achieve better throughput performance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=asymmetric%20traffic" title="asymmetric traffic">asymmetric traffic</a>, <a href="https://publications.waset.org/search?q=cooperative%20transmissions" title=" cooperative transmissions"> cooperative transmissions</a>, <a href="https://publications.waset.org/search?q=multihop%20transmissions" title=" multihop transmissions"> multihop transmissions</a>, <a href="https://publications.waset.org/search?q=CDMA" title=" CDMA"> CDMA</a>, <a href="https://publications.waset.org/search?q=FDD" title=" FDD"> FDD</a>, <a href="https://publications.waset.org/search?q=cellular%20systems" title=" cellular systems"> cellular systems</a> </p> <a href="https://publications.waset.org/11534/multihop-cooperative-transmissions-for-asymmetric-traffic-accommodation-in-cdmafdd-cellular-networks" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/11534/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/11534/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/11534/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/11534/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/11534/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/11534/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/11534/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/11534/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/11534/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/11534/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/11534.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1730</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">40</span> Performance Analysis of an Adaptive Threshold Hybrid Double-Dwell System with Antenna Diversity for Acquisition in DS-CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=H.%20Krouma">H. Krouma</a>, <a href="https://publications.waset.org/search?q=M.%20Barkat"> M. Barkat</a>, <a href="https://publications.waset.org/search?q=K.%20Kemih"> K. Kemih</a>, <a href="https://publications.waset.org/search?q=M.%20Benslama"> M. Benslama</a>, <a href="https://publications.waset.org/search?q=Y.%20Yacine"> Y. Yacine</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we consider the analysis of the acquisition process for a hybrid double-dwell system with antenna diversity for DS-CDMA (direct sequence-code division multiple access) using an adaptive threshold. Acquisition systems with a fixed threshold value are unable to adapt to fast varying mobile communications environments and may result in a high false alarm rate, and/or low detection probability. Therefore, we propose an adaptively varying threshold scheme through the use of a cellaveraging constant false alarm rate (CA-CFAR) algorithm, which is well known in the field of radar detection. We derive exact expressions for the probabilities of detection and false alarm in Rayleigh fading channels. The mean acquisition time of the system under consideration is also derived. The performance of the system is analyzed and compared to that of a hybrid single dwell system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Adaptive%20threshold" title="Adaptive threshold">Adaptive threshold</a>, <a href="https://publications.waset.org/search?q=hybrid%20double-dwell%20system" title=" hybrid double-dwell system"> hybrid double-dwell system</a>, <a href="https://publications.waset.org/search?q=CA-CFAR%20algorithm" title="CA-CFAR algorithm">CA-CFAR algorithm</a>, <a href="https://publications.waset.org/search?q=DS-CDMA." title=" DS-CDMA."> DS-CDMA.</a> </p> <a href="https://publications.waset.org/13815/performance-analysis-of-an-adaptive-threshold-hybrid-double-dwell-system-with-antenna-diversity-for-acquisition-in-ds-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/13815/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/13815/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/13815/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/13815/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/13815/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/13815/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/13815/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/13815/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/13815/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/13815/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/13815.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1718</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">39</span> Determining of Threshold Levels of Burst by Burst AQAM/CDMA in Slow Rayleigh Fading Environments</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=F.%20Nejadebrahimi">F. Nejadebrahimi</a>, <a href="https://publications.waset.org/search?q=M.%20ArdebiliPour"> M. ArdebiliPour</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper, we are going to determine the threshold levels of adaptive modulation in a burst by burst CDMA system by a suboptimum method so that the above method attempts to increase the average bit per symbol (BPS) rate of transceiver system by switching between the different modulation modes in variable channel condition. In this method, we choose the minimum values of average bit error rate (BER) and maximum values of average BPS on different values of average channel signal to noise ratio (SNR) and then calculate the relative threshold levels of them, so that when the instantaneous SNR increases, a higher order modulation be employed for increasing throughput and vise-versa when the instantaneous SNR decreases, a lower order modulation be employed for improvement of BER. In transmission step, by this adaptive modulation method, in according to comparison between obtained estimation of pilot symbols and a set of above suboptimum threshold levels, above system chooses one of states no transmission, BPSK, 4QAM and square 16QAM for modulation of data. The expected channel in this paper is a slow Rayleigh fading.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=AQAM" title="AQAM">AQAM</a>, <a href="https://publications.waset.org/search?q=burst" title=" burst"> burst</a>, <a href="https://publications.waset.org/search?q=BER" title=" BER"> BER</a>, <a href="https://publications.waset.org/search?q=BPS" title=" BPS"> BPS</a>, <a href="https://publications.waset.org/search?q=CDMA" title=" CDMA"> CDMA</a>, <a href="https://publications.waset.org/search?q=threshold." title=" threshold."> threshold.</a> </p> <a href="https://publications.waset.org/11255/determining-of-threshold-levels-of-burst-by-burst-aqamcdma-in-slow-rayleigh-fading-environments" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/11255/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/11255/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/11255/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/11255/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/11255/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/11255/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/11255/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/11255/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/11255/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/11255/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/11255.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1533</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">38</span> A Rapid Code Acquisition Scheme in OOC-Based CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Keunhong%20Chae">Keunhong Chae</a>, <a href="https://publications.waset.org/search?q=Seokho%20Yoon"> Seokho Yoon</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>We propose a code acquisition scheme called improved multiple-shift (IMS) for optical code division multiple access systems, where the optical orthogonal code is used instead of the pseudo noise code. Although the IMS algorithm has a similar process to that of the conventional MS algorithm, it has a better code acquisition performance than the conventional MS algorithm. We analyze the code acquisition performance of the IMS algorithm and compare the code acquisition performances of the MS and the IMS algorithms in single-user and multi-user environments.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Code%20acquisition" title="Code acquisition">Code acquisition</a>, <a href="https://publications.waset.org/search?q=optical%20CDMA" title=" optical CDMA"> optical CDMA</a>, <a href="https://publications.waset.org/search?q=optical%20orthogonal%0D%0Acode" title=" optical orthogonal code"> optical orthogonal code</a>, <a href="https://publications.waset.org/search?q=serial%20algorithm." title=" serial algorithm."> serial algorithm.</a> </p> <a href="https://publications.waset.org/10000869/a-rapid-code-acquisition-scheme-in-ooc-based-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/10000869/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/10000869/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/10000869/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/10000869/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/10000869/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/10000869/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/10000869/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/10000869/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/10000869/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/10000869/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/10000869.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2157</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">37</span> Interference Reduction Technique in Multistage Multiuser Detector for DS-CDMA System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Lokesh%20Tharani">Lokesh Tharani</a>, <a href="https://publications.waset.org/search?q=R.P.Yadav"> R.P.Yadav</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the results related to the interference reduction technique in multistage multiuser detector for asynchronous DS-CDMA system. To meet the real-time requirements for asynchronous multiuser detection, a bit streaming, cascade architecture is used. An asynchronous multiuser detection involves block-based computations and matrix inversions. The paper covers iterative-based suboptimal schemes that have been studied to decrease the computational complexity, eliminate the need for matrix inversions, decreases the execution time, reduces the memory requirements and uses joint estimation and detection process that gives better performance than the independent parameter estimation method. The stages of the iteration use cascaded and bits processed in a streaming fashion. The simulation has been carried out for asynchronous DS-CDMA system by varying one parameter, i.e., number of users. The simulation result exhibits that system gives optimum bit error rate (BER) at 3rd stage for 15-users. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Multi-user%20detection%20%28MUD%29" title="Multi-user detection (MUD)">Multi-user detection (MUD)</a>, <a href="https://publications.waset.org/search?q=multiple%20accessinterference%20%28MAI%29" title=" multiple accessinterference (MAI)"> multiple accessinterference (MAI)</a>, <a href="https://publications.waset.org/search?q=near-far%20effect" title=" near-far effect"> near-far effect</a>, <a href="https://publications.waset.org/search?q=decision%20feedback%20detector" title=" decision feedback detector"> decision feedback detector</a>, <a href="https://publications.waset.org/search?q=successive%20interference%20cancellation%20detector%20%28SIC%29%20and%20parallelinterference%20cancellation%20%28PIC%29%20detector." title="successive interference cancellation detector (SIC) and parallelinterference cancellation (PIC) detector.">successive interference cancellation detector (SIC) and parallelinterference cancellation (PIC) detector.</a> </p> <a href="https://publications.waset.org/11184/interference-reduction-technique-in-multistage-multiuser-detector-for-ds-cdma-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/11184/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/11184/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/11184/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/11184/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/11184/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/11184/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/11184/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/11184/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/11184/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/11184/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/11184.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1762</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">36</span> Comparison of Multi-User Detectors of DS-CDMA System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Kavita%20Khairnar">Kavita Khairnar</a>, <a href="https://publications.waset.org/search?q=Shikha%20Nema"> Shikha Nema</a> </p> <p class="card-text"><strong>Abstract:</strong></p> DS-CDMA system is well known wireless technology. This system suffers from MAI (Multiple Access Interference) caused by Direct Sequence users. Multi-User Detection schemes were introduced to detect the users- data in presence of MAI. This paper focuses on linear multi-user detection schemes used for data demodulation. Simulation results depict the performance of three detectors viz-conventional detector, Decorrelating detector and Subspace MMSE (Minimum Mean Square Error) detector. It is seen that the performance of these detectors depends on the number of paths and the length of Gold code used. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Cross%20Correlation%20Matrix" title="Cross Correlation Matrix">Cross Correlation Matrix</a>, <a href="https://publications.waset.org/search?q=MAI" title=" MAI"> MAI</a>, <a href="https://publications.waset.org/search?q=Multi-UserDetection" title=" Multi-UserDetection"> Multi-UserDetection</a>, <a href="https://publications.waset.org/search?q=Multipath%20Effect." title=" Multipath Effect."> Multipath Effect.</a> </p> <a href="https://publications.waset.org/290/comparison-of-multi-user-detectors-of-ds-cdma-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/290/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/290/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/290/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/290/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/290/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/290/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/290/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/290/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/290/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/290/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/290.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2113</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">35</span> A Comparison of Adaline and MLP Neural Network based Predictors in SIR Estimation in Mobile DS/CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Nahid%20Ardalani">Nahid Ardalani</a>, <a href="https://publications.waset.org/search?q=Ahmadreza%20Khoogar"> Ahmadreza Khoogar</a>, <a href="https://publications.waset.org/search?q=H.%20Roohi"> H. Roohi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper we compare the response of linear and nonlinear neural network-based prediction schemes in prediction of received Signal-to-Interference Power Ratio (SIR) in Direct Sequence Code Division Multiple Access (DS/CDMA) systems. The nonlinear predictor is Multilayer Perceptron MLP and the linear predictor is an Adaptive Linear (Adaline) predictor. We solve the problem of complexity by using the Minimum Mean Squared Error (MMSE) principle to select the optimal predictors. The optimized Adaline predictor is compared to optimized MLP by employing noisy Rayleigh fading signals with 1.8 GHZ carrier frequency in an urban environment. The results show that the Adaline predictor can estimates SIR with the same error as MLP when the user has the velocity of 5 km/h and 60 km/h but by increasing the velocity up-to 120 km/h the mean squared error of MLP is two times more than Adaline predictor. This makes the Adaline predictor (with lower complexity) more suitable than MLP for closed-loop power control where efficient and accurate identification of the time-varying inverse dynamics of the multi path fading channel is required. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Power%20control" title="Power control">Power control</a>, <a href="https://publications.waset.org/search?q=neural%20networks" title=" neural networks"> neural networks</a>, <a href="https://publications.waset.org/search?q=DS%2FCDMA%20mobilecommunication%20systems." title=" DS/CDMA mobilecommunication systems."> DS/CDMA mobilecommunication systems.</a> </p> <a href="https://publications.waset.org/5727/a-comparison-of-adaline-and-mlp-neural-network-based-predictors-in-sir-estimation-in-mobile-dscdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/5727/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/5727/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/5727/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/5727/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/5727/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/5727/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/5727/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/5727/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/5727/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/5727/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/5727.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2515</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">34</span> Performance Analysis of Selective Adaptive Multiple Access Interference Cancellation for Multicarrier DS-CDMA Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Maged%20Ahmed">Maged Ahmed</a>, <a href="https://publications.waset.org/search?q=Ahmed%20El-Mahdy"> Ahmed El-Mahdy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> <p>In this paper, Selective Adaptive Parallel Interference Cancellation (SA-PIC) technique is presented for Multicarrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) scheme. The motivation of using SA-PIC is that it gives high performance and at the same time, reduces the computational complexity required to perform interference cancellation. An upper bound expression of the bit error rate (BER) for the SA-PIC under Rayleigh fading channel condition is derived. Moreover, the implementation complexities for SA-PIC and Adaptive Parallel Interference Cancellation (APIC) are discussed and compared. The performance of SA-PIC is investigated analytically and validated via computer simulations.</p> <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=Adaptive%20interference%20cancellation" title="Adaptive interference cancellation">Adaptive interference cancellation</a>, <a href="https://publications.waset.org/search?q=communicationsystems" title=" communicationsystems"> communicationsystems</a>, <a href="https://publications.waset.org/search?q=multicarrier%20signal%20processing" title=" multicarrier signal processing"> multicarrier signal processing</a>, <a href="https://publications.waset.org/search?q=spread%20spectrum" title=" spread spectrum"> spread spectrum</a> </p> <a href="https://publications.waset.org/2963/performance-analysis-of-selective-adaptive-multiple-access-interference-cancellation-for-multicarrier-ds-cdma-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/2963/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/2963/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/2963/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/2963/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/2963/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/2963/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/2963/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/2963/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/2963/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/2963/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/2963.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">1852</span> </span> </div> </div> <div class="card publication-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">33</span> Performance Analysis of a Free-Space Optical Code Division Multiple Access through Atmospheric Turbulence Channel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/search?q=Tanveer%20Ahmed%20Bhuiyan">Tanveer Ahmed Bhuiyan</a>, <a href="https://publications.waset.org/search?q=Samiul%20Hayder%20Choudhury"> Samiul Hayder Choudhury</a>, <a href="https://publications.waset.org/search?q=Asif%20Al%20-%20Rasheed"> Asif Al - Rasheed</a>, <a href="https://publications.waset.org/search?q=S.P.%20Majumder"> S.P. Majumder</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, the effect of atmospheric turbulence on bit error probability in free-space optical CDMA scheme with Sequence Inverse Keyed (SIK) optical correlator receiver is analyzed. Here Intensity Modulation scheme is considered for transmission. The turbulence induced fading is described by the newly introduced gamma-gamma pdf[1] as a tractable mathematical model for atmospheric turbulence. Results are evaluated with Gold and Kasami code & it is shown that Gold sequence can be used for more efficient transmission than Kasami sequence in an atmospheric turbulence channel. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/search?q=CDMA" title="CDMA">CDMA</a>, <a href="https://publications.waset.org/search?q=gamma-gamma%20pdf" title=" gamma-gamma pdf"> gamma-gamma pdf</a>, <a href="https://publications.waset.org/search?q=atmospheric%0Aturbulence" title=" atmospheric turbulence"> atmospheric turbulence</a>, <a href="https://publications.waset.org/search?q=Kasami" title=" Kasami"> Kasami</a>, <a href="https://publications.waset.org/search?q=Gold" title=" Gold"> Gold</a>, <a href="https://publications.waset.org/search?q=SIK" title=" SIK"> SIK</a>, <a href="https://publications.waset.org/search?q=BER" title=" BER"> BER</a>, <a href="https://publications.waset.org/search?q=Power%20Penalty" title=" Power Penalty"> Power Penalty</a>, <a href="https://publications.waset.org/search?q=FSO." title=" FSO."> FSO.</a> </p> <a href="https://publications.waset.org/2607/performance-analysis-of-a-free-space-optical-code-division-multiple-access-through-atmospheric-turbulence-channel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/2607/apa" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">APA</a> <a href="https://publications.waset.org/2607/bibtex" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">BibTeX</a> <a href="https://publications.waset.org/2607/chicago" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Chicago</a> <a href="https://publications.waset.org/2607/endnote" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">EndNote</a> <a href="https://publications.waset.org/2607/harvard" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">Harvard</a> <a href="https://publications.waset.org/2607/json" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">JSON</a> <a href="https://publications.waset.org/2607/mla" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">MLA</a> <a href="https://publications.waset.org/2607/ris" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">RIS</a> <a href="https://publications.waset.org/2607/xml" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">XML</a> <a href="https://publications.waset.org/2607/iso690" target="_blank" rel="nofollow" class="btn btn-primary btn-sm">ISO 690</a> <a href="https://publications.waset.org/2607.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">2133</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/search?q=CDMA&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/search?q=CDMA&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/search?q=CDMA&page=2" rel="next">&rsaquo;</a></li> </ul> </div> </main> <footer> <div id="infolinks" class="pt-3 pb-2"> <div class="container"> <div style="background-color:#f5f5f5;" class="p-3"> <div class="row"> <div class="col-md-2"> <ul class="list-unstyled"> About <li><a href="https://waset.org/page/support">About Us</a></li> <li><a href="https://waset.org/page/support#legal-information">Legal</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/WASET-16th-foundational-anniversary.pdf">WASET celebrates its 16th foundational anniversary</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Account <li><a href="https://waset.org/profile">My Account</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Explore <li><a href="https://waset.org/disciplines">Disciplines</a></li> <li><a href="https://waset.org/conferences">Conferences</a></li> <li><a href="https://waset.org/conference-programs">Conference Program</a></li> <li><a href="https://waset.org/committees">Committees</a></li> <li><a href="https://publications.waset.org">Publications</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Research <li><a href="https://publications.waset.org/abstracts">Abstracts</a></li> <li><a href="https://publications.waset.org">Periodicals</a></li> <li><a href="https://publications.waset.org/archive">Archive</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Open Science <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Philosophy.pdf">Open Science Philosophy</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Award.pdf">Open Science Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Society-Open-Science-and-Open-Innovation.pdf">Open Innovation</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Postdoctoral-Fellowship-Award.pdf">Postdoctoral Fellowship Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Scholarly-Research-Review.pdf">Scholarly Research Review</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Support <li><a href="https://waset.org/page/support">Support</a></li> <li><a href="https://waset.org/profile/messages/create">Contact Us</a></li> <li><a href="https://waset.org/profile/messages/create">Report Abuse</a></li> </ul> </div> </div> </div> </div> </div> <div class="container text-center"> <hr style="margin-top:0;margin-bottom:.3rem;"> <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" class="text-muted small">Creative Commons Attribution 4.0 International License</a> <div id="copy" class="mt-2">© 2024 World Academy of Science, Engineering and Technology</div> </div> </footer> <a href="javascript:" id="return-to-top"><i class="fas fa-arrow-up"></i></a> <div class="modal" id="modal-template"> <div class="modal-dialog"> <div class="modal-content"> <div class="row m-0 mt-1"> <div class="col-md-12"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> </div> </div> <div class="modal-body"></div> </div> </div> </div> <script src="https://cdn.waset.org/static/plugins/jquery-3.3.1.min.js"></script> <script src="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/js/bootstrap.bundle.min.js"></script> <script src="https://cdn.waset.org/static/js/site.js?v=150220211556"></script> <script> jQuery(document).ready(function() { /*jQuery.get("https://publications.waset.org/xhr/user-menu", function (response) { jQuery('#mainNavMenu').append(response); });*/ jQuery.get({ url: "https://publications.waset.org/xhr/user-menu", cache: false }).then(function(response){ jQuery('#mainNavMenu').append(response); }); }); </script> </body> </html>