Sum-rate maximization in RIS-aided MU-MIMO system with movable antenna

Reconfigurable intelligent surface (RIS), as a promising technology, has been widely used in urban traffic communication system due to the short wavelength in mmWave communications. Meanwhile, movable antenna (MA) gains great research interest for its ability to influence spatial channel path. It can be deployed in a desired position to achieve higher spatial diversity gains. Given the limited research on combining RIS with movable antennas, this paper proposes an algorithm which jointly optimizes the antenna position and the phase shift of the RIS using beamforming matrix as a bridge to maximize the sum rate. Simulation results show the effectiveness of the proposed method.