An Orthogonal Projection Optimization Algorithm for Multi-User MIMO Channels

We consider a multi-user (MU) multiple-input multiple-output (MIMO) channel where each node is equipped with multiple antennas. An orthogonal projection optimization (OPO) algorithm is proposed based on linear transmit beamforming and receive combining. The performance of the OPO algorithm is analyzed which discloses its convergence characteristics. The complexity of the OPO algorithm is also addressed and a computationally efficient algorithm is developed. The OPO algorithm is applied to both uplink and downlink MU MIMO systems, and simulation results show its excellent performance.