Downlink transmission scheme for massive MU-MIMO system with reduced CSI

This paper consider the problem of obtaining the channel state information (CSI) in downlink massive MU-MIMO systems. As a key technology of future wireless communication, massive MIMO has attracted widespread interest, however, amount of the CSI required became a bottleneck for practical application, especially for FDD transmitting method. In this paper, we propose a novel transmitting scheme, combined user-grouping, intra-group user-scheduling and downlink MU-MIMO precoding, which can reduce the amount of CSI feedback. Our results indicate that the proposed method can reduce the amount of CSI greatly, and have a significant strength with the UEs number increasing.