Joint Beamforming Design for RIS-Aided Secure Integrated Sensing and Communication Systems
Haitao Zhao, Fengjing Wu, Wenchao Xia, Yao Zhang, Yiyang Ni, Hongbo Zhu
Abstract
This letter investigates the physical layer security of reconfigurable intelligent surface (RIS) aided integrated-sensing-and-communication (ISAC) systems, in which the high-power radar signal is used as the interference to disturb the eavesdropper. We formulate a joint beamforming optimization problem of active beamforming of base station and passive beamforming of RIS to minimize the maximum eavesdropping signal-to-interference-plus-noise (SINR). To find its solution, we decompose the original problem into two subproblems and then use the alternating optimization (AO) technique based on the fraction programming (FP) and semi-definite programming (SDP) methods. Simulation results show that the proposed FP-SDP-AO algorithm has good convergence performance and can effectively suppress the SINR of eavesdroppers while maintaining a satisfactory quality of service for legitimate users.