Journal of South China University of Technology(Natural Science Edition) ›› 2023, Vol. 51 ›› Issue (3): 110-123.doi: 10.12141/j.issn.1000-565X.220308

Special Issue: 2023年电子、通信与自动控制

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Transmit Power Minimization Algorithms for IRS-Assisted Cognitive Simultaneous Wireless Information and Power Transfer Networks

ZHANG Guangchi1 LE Wenying1 PANG Haijian1 CUI Miao1 WU Qingqing2   

  1. 1.School of Information Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
    2.School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2022-05-24 Online:2023-03-25 Published:2022-09-07
  • Contact: 张广驰(1982-),男,博士,教授,主要从事新一代无线通信技术研究。 E-mail:gczhang@gdut.edu.cn
  • About author:张广驰(1982-),男,博士,教授,主要从事新一代无线通信技术研究。
  • Supported by:
    the Special Support Plan for High-Level Talents of Guangdong Province(2019TQ05X409);the Science and Technology Plan Project of Guangdong Province(2022A0505020008);the Open Fund Project of Jiangxi Military-Civilian Integration Beidou Navigation Key Laboratory(2022JXRH0004)

Abstract:

Intelligent reflecting surface (IRS) and cognitive simultaneous wireless information and power transfer (SWIPT) are regarded as potential key technologies to improve energy efficiency and spectrum utilization of wireless communication systems. This paper studied the IRS-aided cognitive SWIPT network based on a nonlinear energy harvesting model. In the network, a secondary transmitter simultaneously transmits information and energy to multiple secondary receivers, and each secondary receiver adopts the power splitting scheme to realize information decoding and energy harvesting. The aim is to minimize the transmit power of the secondary user transmitter by jointly optimizing the beamforming vector of the secondary transmitter, the power splitting coefficients of the secondary receivers, and the phase shifts of the IRS. In order to guarantee the information and energy transmission efficiency of the secondary users and limit the co-channel interference from the secondary users to the primary users, it is considered that the secondary receivers have the constraints of the minimum received signal-to-interference noise ratio, the minimum energy harvesting amount, and the values of power splitting coefficients, the secondary transmitter has the constraints of the maximum interference power values to the primary users, and the IRS has the constraints on its reflection phase shifts. The considered optimization problem is a non-convex quadratically constrained quadratic program problem with highly coupled optimization variables, which is difficult to solve. An alternating optimization algorithm based on the semidefinite relaxation and sequential rank one constraint relaxation techniques was proposed to solve the problem efficiently. In order to reduce the computation complexity, a low-complexity optimization algorithm based on IRS element grouping was further proposed. Simulation results show that compared to several benchmark algorithms, the proposed algorithms can effectively reduce the transmit power of the secondary transmitter.

Key words: intelligent reflecting surface, cognitive simultaneous wireless information and power transfer, nonlinear energy harvesting, power splitting, sequential rank one constraint relaxation

CLC Number: