Maximizing the minimum SINR of V-BLAST system by power control

Power control is often used to improve the performance of V-BLAST system with MMSE-SIC receiver. Existing algorithms focus on reducing average uncoded BER of all subchannels while overlooking the performance of the worst subchannel. As a consequence, the worst subchannel may severely limit the overall performance, e.g., in a system where coding is independent across all subchannels. In order to guarantee the performance of the worst subchannel, we design a new power control algorithm to maximize the minimum post-detection SINR of all subchannels. Simulation results show that V-BLAST integrated with the proposed algorithm provides a significant reduction in coded BER of both the worst subchannel and the overall system. Furthermore, compared with existing algorithms, the new algorithm does not lose much in terms of average uncoded BER.