ZF Beamforming Performance Analysis for Multiuser Spatial Multiplexing with Imperfect Channel Feedback

In this paper, we focus on downlink zero forcing (ZF) beamforming design scheme for multiuser (MU) spatial multiplexing (SM) multiple-input multiple-output (MIMO) systems. Based on the minimum average probability of symbol error (PSE), we give the optimal design method of the beamforming weight matrices. Furthermore, we derive the upper bound PSEs to evaluate the impact of channel feedback errors on the system performance. Comparison of the upper bounds of the average PSE for several schemes shows that the downlink ZF beamforming for multiuser spatial multiplexing MIMO schemes provide almost the same performance as the SU beamforming scheme.