User and Antenna Joint Selection in Multi-User Large-Scale MIMO Downlink Networks

Abstract

In this paper, we investigate a user and antenna joint selection problem in multi-user large-scale MIMO downlink networks, where a BS with N transmit antennas serves K users, and N is much larger than K. The BS activates only S(S S N) antennas for data transmission to reduce hardware cost and computation complexity, and selects the set of users to which data is to be transmitted by maximizing the sum-rate. The optimal user and antenna joint selection scheme based on exhaustive search causes considerable computation complexity. Thus, we propose a new joint selection algorithm with low complexity and analyze the performance of the proposed scheme in terms of sum-rate and complexity. When S = 7, N = 10, K = 5, and SNR=10 dB, the sum-rate of the proposed scheme is 5.19( lower than that of the optimal scheme, while the computation complexity of the proposed scheme is reduced by 99.090 compared to that of the optimal scheme.