Robust THP Transceiver Design for MIMO Interference Channel

This letter focuses on robust Tomlinson-Harashima precoding (THP) transceiver optimization for multiple-input multiple-output (MIMO) interference channel, where a bounded channel error model is assumed. Two optimization problems are formulated as minimizing the maximum per-user mean square error (MSE) and sum MSE with per-transmitter power constraint, respectively. Since both optimization problems are not convex, a sub-optimal alternating optimization method is proposed to iteratively update the transmit feedback matrix, precoding matrix and receive equalization matrix of THP transceiver until convergence. We show that the two problems of three matrix variables can be formulated as semidefinite program (SDP) when any two of three matrices are fixed, thus making the problems computationally tractable. Simulation results demonstrate that the proposed THP transceivers can improve the performance over the linear transceivers and are robust to the imperfect channel state information (CSI).