Precoder design for MIMO systems with iterative equalization

This paper is concerned with precoder design for multiple-input multiple-output (MIMO) systems with iterative equalization. We first consider the case of no channel state information at the transmitter (CSIT). Based on evolution analysis, we derive the optimized precoder that minimizes the bit error rate (BER) of the system. We show that, with the optimized precoder, the linear precoding and iterative equalization scheme can achieve a genie-aided performance upper bound at high signal-to-noise ratio (SNR). We further consider the precoder design with perfect CSIT. We show that the precoder design problem reduces to a convex power-allocation problem that can be efficiently solved using standard convex programming tools. Numerical results are provided to demonstrate the performance advantages of the proposed scheme over its counterparts.