Joint Beamforming Optimization for RIS-Aided Full-Duplex Communication

In this letter, we investigate the joint beamforming optimization for a reconfigurable intelligent surface (RIS)-aided multi-antenna full-duplex communication system. Our goal is to minimize the total transmit power by jointly optimizing the active beamforming at the sources and the passive beamforming at the RIS, subject to the minimum data rate requirements at the sources. To solve the non-convex problem, an efficient algorithm is proposed by utilizing the alternating optimization framework to iteratively optimize variables. Specifically, in each iteration, the active beamforming vectors are obtained by using the semidefinite relaxation (SDR) method and the optimality of the solution is proved, while the successive convex approximation (SCA) method and semidefinite program (SDP) are used to solve the passive beamforming optimization problem. Numerical results verify the convergence and effectiveness of the proposed algorithm, and further reveal the performance gain compared with the RIS assisted half-duplex system.