Transmission with linear precoding and limited feedback in multiuser MIMO systems

Abstract

In this paper, a novel multiuser MIMO downlink transmission scheme with limited feedback and linear precoding is proposed, using maximum signal-to-jamming and noise ratio (SJNR) criterion. According to the analysis of the criterion, it is shown that the multiplexed users with high channel gain but low correlation with each other may bring high system capacity. For the limited feedback scenario, we design the user preselection scheme and the quantized feedback of the users' channel vectors. The preselection scheme, taking advantages of threshold and the norm of inner product of the channel vector with orthogonal random beamforming, significantly reduces the feedback load and preserves the tradeoff between the channel gain and correlation of users. Simulation results show that the proposed scheme has much higher capacity but lower feedback load compared with existing schemes.