Max -Min Rate Optimization for Group- Transmissive RIS- Based Transmitter Architectures

Transmissive reconfigurable intelligent surface (RIS) is considered as a promising technology for future wireless networks due to its low power consumption and low cost. To guarantee the user's fairness, in this paper, we propose a group-transmissive RIS scheme and formulate a max-min fairness problem via a joint optimization of the RIS transmission coefficient and power allocation. To solve it, we develop an alternating optimization algorithm to divide the original optimization problem into two subproblems. The semidefinite relaxation and successive convex approximation are used to solve each one. Then two subproblems are solved alternately until convergence and the final solutions are obtained. Finally, we present simulation results to validate the efficacy of our proposed scheme.