Precoding scheme maximizing SINR for MIMO broadcast channels

An improved precoding scheme for multiple-input multiple-output (MIMO) broadcast channel (BC) is proposed to maximize the detection signal-to-interference-plus-noise ratio (SINR) at user side based on the vector-perturbation technique. With the derived maximum detection SINR criterion, a new tree search based detection algorithm, called iterative M-algorithm (IMA), is utilized to find out the optimal perturbation vector. Simulations show that the proposed scheme outperforms the existing schemes which are based on the maximum detection signal-to-noise ratio (SNR) criterion. Moreover, the proposed scheme can achieve the same bit error rate (BER) performance as the vector-perturbation scheme based on sphere encoder and the maximum detection SINR criterion, with guaranteed polynomial worst-case complexity.