Throughput Maximization of Hybrid Active/ Passive IRS-Assisted SWIPT System

Abstract

The integration of the intelligent reflecting surface(IRS) with simultaneous wireless information and power transfer(SWIPT) has emerged as a cost-effective and efficient solution to enhance the performance of information and energy transfer. In this research, a hybrid active/ passive IRS-assisted SWIPT system is proposed. Specifically, an active IRS(AIRS) and a passive IRS(PIRS) are deployed in the SWIPT system to facilitate a multiantenna base station(BS) in simultaneously delivering information and energy to multiple information users(IUs) and energy users(EUs). The objective is to maximize the sum throughput by jointly optimizing the transmitter beamforming and the reflection coefficient matrices of the AIRS and the PIRS while satisfying the transmitter power constraints, the energy harvesting(EH) requirements of EUs, and the AIRS amplification power limitations. However, the optimization variables are highly coupled and cannot be solved directly. To tackle this complex problem, we propose an efficient algorithm based on alternating optimization(AO) and semi-definite relaxation(SDR) techniques to obtain high-quality solutions. Simulation results demonstrate that the hybrid active/ passive IRS- assisted SWIPT system significantly enhances throughput performance and outperforms benchmark systems.

Keywords

simultaneous wireless information and power transfer(SWIPT) / intelligent reflecting surface(IRS) / hybrid active/ passive IRS / throughput optimization

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Funding

National Natural Science Foundation of China(62301141)