Capacity Evaluation of Various Multiuser MIMO Schemes in Downlink Cellular Environments

The CDFs of the throughput per user and the average cell throughputs for various multiuser MIMO schemes are evaluated. The effects of multiplexing, multiuser diversity, and array gain are observed. Also, the performance gaps between the optimal and various suboptimal schemes are shown. Here, it is surmised that the suboptimal schemes such as the GZF and VP, which also have potential to be improved further, are good candidates for next generation communications. However, all of the previous schemes need perfect channel state information at the transmitter for implementation. Examining the robustness of these schemes against channel uncertainty and the exact complexity comparison of each system remains as work to be undertaken.