Sum Secrecy Rate Maximization for IRS-Aided SWIPT System with Artificial Noise

In this paper, we probe into a simultaneous wireless information and power transfer system, while accommodating legitimate users and eavesdroppers with the assistance of an intelligent reflecting surface. To maximize the sum secrecy rate of the system through the joint optimization of the beamforming and artificial noise covariance matrix at the access point, the phase shift matrix of the intelligent reflecting surface, and the power splitting ratio of LUs. The problem is non-convex since the intricate coupling relationship among variables. To overcome this challenge, alternating optimization method is used to separate the original problem into three subproblems for effective resolution. Next, we employ the semi-definite relaxation, Taylor formula, and successive convex approximation to convert the subproblems into convex ones. The effectiveness of our proposed algorithm is proved by the numerical simulation results.