Robust Transmit Beamforming Design for Full-Duplex Point-to-Point MIMO Systems

In this paper we address the beamforming design problem for a full-duplex point-to-point MIMO system under imperfect channel state information (CSI). More specifically, we consider the worst-case beamforming design which minimizes the required transmit power subject to total SINR requirements and self-interference constraints which guarantee that the fullduplex device will work in the limited dynamic range of the receiver. This optimization problem is non-convex since it involves an infinite number of constraints which are due to the channel error model. Nevertheless, by applying the S-procedure and the Schur complement, it is possible to transform the original problem into a convex semidefinite programming problem which can be solved using the standard interior-point algorithm. The simulation results have shown that a significant gain is obtained via the proposed robust design especially when the channel error intensity is high and the array size is large.