Throughput Maximization in Multiuser MIMO Downlink with Individual QoS Constraints

This paper addresses the problem of maximizing the throughput with a total power and individual rate constraints for a multiuser multiple-input multiple-output (MIMO) antenna system in the downlink using generalized beamforming. Channel state information at the transmitter (CSIT) and the receivers (CSIR) is assumed available. An iterative approach is proposed which alternates between optimizing the power allocation, transmit antenna vectors and receive antenna vectors. Moreover, we also show that the throughput in the proposed algorithm has a monotonic non-decreasing property and hence the algorithm is convergent. Simulation results demonstrate that this algorithm can substantially increase the throughput compared with a zero-forcing solution (GZF) and at the same time it can guarantee the individual users´ transmission rates