Maximizing Sum Rate in Wireless Communication Systems with Dual Intelligent Reflecting Surfaces

Intelligent Reflecting Surface (IRS) has emerged as a promising technology to significantly enhance the performance of wireless communication systems. This paper presents a comprehensive study of a double-IRS assisted multi-user communication system, proposing a novel joint optimization method. A joint optimization approach for passive beamforming in dual IRSs and active beamforming at the base station is applied to maximize the system sum rate. The problem is formulated as a non-convex optimization challenge, addressed through a proposed low-complexity iterative algorithm based on alternating optimization with semi-closed-form solutions. Simulation results validate our theoretical analysis and demonstrate the significant performance advantages of the proposed scheme.