Robust transceiver optimization for non-regenerative MIMO relay systems

In this paper, we design a robust relay transceiver for non-regenerative MIMO relay system where imperfect channel state information (CSI) is available at the relay node. The CSI errors of relay to destination link at the relay node are assumed to be norm bounded due to the quantization and feedback. And the worst-case design approach is consdiered. The robust optimization aims to minimize worst-case sum mean-square errors (MSE) with the power constraints at the relay under channel uncertainty. An iterative algorithm is proposed for the optimization. Further, the subproblems in the iteration are proven to be equivalent to semidefinite programming representations with efficient solutions. Simulation results verify the robustness of the proposed MIMO relay transceivers when compared to the non-robust design.