Reconfigurable Intelligent Surface-Assisted Multi-Cell MISO Communication Systems Exploiting Statistical CSI

In this letter, we investigate the reconfigurable intelligent surface (RIS) assisted multi-cell downlink multi-input single-output system under the assumption of only statistical channel state information at the base stations and RIS. Firstly, a closed-form ergodic weighted sum rate approximation is obtained. Then, based on this approximation, we propose an approximate optimal joint beamforming vectors and RIS phase shift matrix design algorithm utilizing the fractional programming and complex circle manifold. Simulation results show that the proposed low-complexity algorithm performs well.