Robust transceiver design for MIMO relay systems with direct link under imperfect channel state information

Abstract

In this paper, the robust transceiver design for multiple-input-multiple-output relay systems with direct link is investigated in the presence of imperfect channel state information. Constrained by maximum power at transmitting and relay terminal, a joint optimised algorithm is proposed based on the minimum mean-squared error rule. Specifically, given the solution of the linear processing matrix of the receiver, the constrained optimisation problem can be transformed into two sub-convex optimisation problems with respect to object variables, and the precoding matrix can then be obtained by using projected gradient method and CVX toolbox. Finally, an alternating algorithm is proposed for the joint design, and simulation results indicated that the proposed design scheme can achieve better performance.