Research on Physical Layer Security Communication Based on Distributed Intelligent Reflective Surface

Intelligent Reflecting Surface (IRS) has been widely used in the after 5G and 6G to increase the communication efficiency by adjusting the wireless transmission channels in real-time. In this paper, the use of distributed IRSs to maximize the secrecy rate is investigated. Considering the constraints for the power, constant-mode and the correlation between the IRS links, the optimization problem of the secrecy rate maximization based on the active beamforming of the base station and IRSs' phase shifts is formulated. An efficient algorithm is proposed to solve the non-convex optimization problem by using the fractional programming and manifold optimization methods. Finally, simulation results confirm, compared with the conservative methods, the proposed algorithm can significantly improve the secrecy communication rate. Furthermore, the results unveil that the distributed IRS scheme achieves a significant secure performance improvement over the centralized IRS.