Analysis and Optimization for RIS-Aided Multi-Pair Communications Relying on Statistical CSI

In this paper, we investigate a reconfigurable intelligent surface (RIS) aided multi-pair communication system, in which users exchange information via an RIS. We derive approximate expression for the achievable rate by assuming that statistical channel state (CSI) is available. A genetic algorithm (GA) to solve maximization problem proposed as well. particular, consider implementations of RISs with continuous phase shifts (CPSs) and discrete (DPSs). Simulation results verify obtained show GA method has almost same performance globally optimal solution. addition, numerical three quantization bits can achieve large portion CPSs setup.