IRS辅助C-IoT系统的保密率设计OA

A secrecy rate optimization scheme based on joint beamforming is proposed for the C-IoT(Cognitive Internet of Things)communication system with eavesdroppers assisted by IRS(Intelligent Reflecting Surface).In the system model,a multiple-input single-output communication scenario consisting of a transmitter,a primary user,a secondary user,an eavesdropper,and an IRS is considered.Based on this model,the secrecy rate optimization problem is constructed.That is,under the constraints of the total transmit power of the transmitter,the interference power at the primary user side,and the unit modulus constraint of the IRS,the SR(Secrecy Rate)of the system is maximized by jointly optimizing the active and passive beamforming.In the process of implementation,since the formulaic problem is non-convex,the problem is decomposed into two sub-problems by an alternate optimization method:the optimization of the transmitter beamforming matrix and the IRS phase-shift matrix.For the matrix optimization of transmitter beamforming,SDR(Semidefinite Relaxation)method and SCA(Successive Convex Approximation)method are used.The phase shift matrix of IRS is op-timized by Dinkelbach and SCA.The simulation results show that in a MISO system with eavesdroppers,the introduction of IRS to optimize active and passive beamforming effectively improves the system's secrecy rate.