TY - JFULL AU - Parit Kanjanavirojkul and Kiatwarakorn Keeratishananond and Prapun Suksompong PY - 2011/5/ TI - Implementation of SU-MIMO and MU-MIMOGTD-System under Imperfect CSI Knowledge T2 - International Journal of Electronics and Communication Engineering SP - 546 EP - 551 VL - 5 SN - 1307-6892 UR - https://publications.waset.org/pdf/7864 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 52, 2011 N2 - We study the performance of compressed beamforming weights feedback technique in generalized triangular decomposition (GTD) based MIMO system. GTD is a beamforming technique that enjoys QoS flexibility. The technique, however, will perform at its optimum only when the full knowledge of channel state information (CSI) is available at the transmitter. This would be impossible in the real system, where there are channel estimation error and limited feedback. We suggest a way to implement the quantized beamforming weights feedback, which can significantly reduce the feedback data, on GTD-based MIMO system and investigate the performance of the system. Interestingly, we found that compressed beamforming weights feedback does not degrade the BER performance of the system at low input power, while the channel estimation error and quantization do. For comparison, GTD is more sensitive to compression and quantization, while SVD is more sensitive to the channel estimation error. We also explore the performance of GTDbased MU-MIMO system, and find that the BER performance starts to degrade largely at around -20 dB channel estimation error. ER -