关键词: 无线通信, 有源可重构智能表面, 加权总和速率, 自干扰抑制, 拓扑结构设计

Abstract: In order to suppress the self-interference between active reconfigurable intelligent surface (RIS) components and further improve the system capacity, a joint optimization of active RIS topology and precoding design scheme is proposed. Considering the maximum power constraints of base station and active RIS, the optimization problem is established based on the criterion of maximum weighted summation rate (WSR). In order to solve the non-convex problem, the problem is decomposed into two subproblems, active RIS topology and precoding design, and the subproblem is transformed and iteratively optimized by using adaptive tabu search, Lagrange multiplier method and two-dimensional grid search, and the approximate suboptimal solution is obtained. The simulation results show that the WSR of the optimized active RIS is 3.75bit/s/Hz higher than that of the conventional active RIS under ideal conditions. In the presence of self-interference, the proposed scheme only reduces WSR by 0.46% compared with the ideal state, while the conventional active RIS decreases by 1.6%, which proves that the pro-posed scheme can effectively suppress the self-interference between active components.

Key words: Wireless communication, Active reconfigurable intelligent surface, Weighted summation rate, Self-interference suppression, Topological structure design