Multiuser MIMO Downlink Beamforming Based on Group Maximum SINR Filtering

In this paper we aim to solve the multiuser multi- input multi-output (MIMO) downlink beamforming problem. The transmitter is a multi-antenna base-station broadcasting to users. Each user has multiple antennas at the receiver. A solution of the joint transmit-receive beamforming and power allocation under signal-to-interference-plus-noise-ratio (SINR) constraints in this system is proposed. The beamforming filter is a group maximum SINR filter which exploits intra-group cooperation. Taking advantage of the uplink-downlink duality property, the proposed algorithm iteratively computes the transmit-receive beamforming filters and the power allocation matrix. Simulation results verify the superiority of the proposed algorithm over previous works using per stream maximum SINR method.