Grouped multiuser diversity for spatial multiplexing MIMO systems

Focusing on the spatial multiplexing multiuser Multiple-Input Multiple-Output (MIMO) downlink, this paper studies the influence of the spatial fading correlation and the channel estimation error on the system capacity. Two novel grouped multiuser diversity schemes are proposed. The proposed schemes can effectively increase the system capacity by rightly selecting the co-channel users, and can provide a good fairness performance. Both analysis and simulation results show that the schemes are robust for the fading correlation and channel estimation errors. The second scheme can further increase the system capacity compared with the first one, but possesses higher computational complexity.