Physical Layer Security for IRS-Assisted Cognitive Radio Networks

Abstract

In this work, we consider a robust transmission design of Intelligent Reflecting Surface (IRS)-assisted secure Cognitive radio communication system base on imperfect channel state information(ICSI). We aim to minimize the transmit power under the constraint of the secure rate of the secondary user and the interference temperature of the primary user. To solve this problem, we use an alternate optimization method to decouple the problem into two sub-problems that can be solved by iterative optimization. Particularly, the successive convex approximation (SCA) method is used to optimize the active beamforming for the second station, while the penalty convex-concave procedure(CCP) is used to obtain the reflected phase of the IRS. Simulation results illustrate robust design is necessary and can improve the energy efficiency and spectrum efficiency of the system.