Abstract: This paper makes a deep analysis on the linear receiver of spatial multiplexing multi-antenna system.The linear receiver is easy to use,but fails to take advantage of the diversity gain.Aiming at this problem,a fast diversity-multiplexing selection algorithm based on bit error rate(BER) criterion is proposed.The proposed algorithm selects the diversity and multiplexing mode of multi-antenna system based on a low complexity decision criterion,sends a few feedback bits to receiver,and achieves the objective of making full use of the diversity and multiplexing gain of multi-antenna system. Compared with the traditional algorithm,the proposed algorithm gets a better instantaneous diversity gain,has a much lower computational cost and meets real-time and rapidity requirements from multi-antenna communication systems.Simulation results are presented to demonstrate the effectiveness and feasibility of the proposed algorithm.