Journal of Jilin University (Information Science Edition) ›› 2024, Vol. 42 ›› Issue (6): 1041-1047.

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Joint Beamforming Design for IRS-Assisted C-IoT System

SUN Zhenxing1a, SHA Guohui2, NAN Chunping1b, XU Ziang2, LI Xuefeng2    

  1. 1a. Department of Electrical Information Engineering; 1b. Basic Department, Northeast Petroleum University-Qinhuangdao, Qinhuangdao 066004, China; 2. School of Electrical and Information Engineering, Northeast Petroleum University, Daqing 163318, China
  • Received:2023-10-25 Online:2024-12-23 Published:2024-12-23

Abstract: Aiming at the problem of low spectrum efficiency in MIMO(Multiple Input Multiple Output) C-IoT (Cognitive Internet of Things) systems, a block coordinate descent algorithm based on alternating iterative assisted by IRS(Intelligent Reflecting Surface) is proposed. System weighted sum rate is maximized by jointly optimizing active beamforming at secondary transmitter and passive beamforming at IRS, and is constrained by the interference power at the primary receiver, the transmit power at the secondary transmitter, and the unit mode at the IRS. After decomposing the complex non-convex optimization problem into subproblems, the subproblems are processed using the Lagrange Dual method and the Successive Convex Approximation method, respectively. The simulation results show that the proposed algorithm can converge quickly in a multi-antenna user scenario, and the spectrum efficiency of the C-IoT system can be effectively improved by increasing the number of IRS reflective elements or correctly deploying the location of the IRS. 

Key words: intelligent reflecting surface, cognitive internet of things, multiple input multiple output(MIMO), beamforming

CLC Number: 

  • TP929.5