Performance of TD-SCDMA System with Imperfect Beamforming Smart antennas
Chen Bo①; Yang Guang②; Chang Yong-yu①; Yang Da-cheng①
①College of Telecommunications, Beijing University of Posts & Telecommunications, Beijing 100876, China; ②France Telecom R&D Beijing, Beijing 100080, China
Abstract:In practical wireless communication networks, downlink beamforming weights at the node B of smart antenna systems can be deteriorated due to variation of spatial signal vectors corresponding to mobile users or DOA estimation error. In this paper, the methodology for smart antenna systems with imperfect beamforming is proposed, the performance of smart antenna systems is studied in existing beamforming error scenarios and the accepted tolerance of the beamforming error in TD-SCDMA systems is researched on from the aspect of system capacity. On the one hand, the theoretical and simulation results show that beamforming accuracy of the smart antenna systems have great effect on the system capacity. On the other hand, they also indicate that the performance deterioration is remarkable if the beamforming error exceeds a threshold which is related to the system load.