As one of the key technologies in the sixth-generation (6G) wireless network, reconfigurable intelligent surfaces (RIS) have numerous applications in wireless communication. This study focuses on the RIS-assisted secure wireless communication system. Specifically, we deploy double-RIS in the system, which takes into account the hardware impairments of the transceivers. By jointly designing the transmit beamforming of the base station (BS) and the phase shift matrix of the RIS, we can enhance the signal strength at the legitimate user and suppress the signal strength at the eavesdropper to maximize the secrecy rate. To address the high coupling of the optimization variables, the block coordinate descent (BCD) method is employed to decompose the problem into three sub-problems for optimization. The sub-problem of optimizing the beamforming variables is transformed into a convex problem using the successive convex approximation (SCA) method. Furthermore, the sub-problem of optimizing the RIS phase shift is solved using the semi-definite relaxation (SDR) method. Simulation results illustrate that the proposed robust design scheme has better performance than the traditional non-robust scheme, which ignores hardware impairments.
Double-RIS Aided Secure Wireless Communication System with Robust Design
10.10.2023
1057808 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch