Cooperative Precoding, Beamforming and Power Allocation in MU-MIMO Relay Networks

In this paper, we investigate a cooperative transmission method employing precoding, beamforming and power allocation for a multi-user multiple-input multiple-output (MU-MIMO) relay network. In the proposed scheme, the interference is canceled by using the combination of beamforming weights and Tomlinson-Harashima precoding (THP). To achieve symbol error rate (SER) fairness among different users and further improve the performance of MU-MIMO relay networks, we propose a low-complexity power allocation (LC-PA) that allocates power to each user so that the signal-to-interference-and-noise-ratio (SINR) for all users are equal. The simulation results show that the SER performance of the proposed scheme considerably outperforms other existing schemes under the same configuration.