RIS-Aided Constant-Envelope Beamforming for Multiuser Wireless Power Transfer:A Max-Min Approach  

作　　者：Huiyuan Yang Chang Cai Xiaojun Yuan Yingchang Liang 

机构地区：[1]Center for Intelligent Networking and Communications,University of Electronic Science and Technology of China,Chengdu 611731,China

出　　处：《China Communications》2021年第3期80-90,共11页中国通信（英文版）

基　　金：supported by General Program of National Natural Science Foundation of China(No.62071090);Sichuan Science and Technology Program(No.2021YFH0014).

摘　　要：As a revolutionary hardware technology that can reconfigure the propagation environment,reconfigurable intelligent surfaces(RISs)have been regarded as a promising solution to enhance wireless networks.In this paper,we consider a multiuser multiple-input single-output(MISO)wireless power transfer(WPT)system,which is assisted by several RISs.In order to improve energy efficiency and reduce hardware cost,we consider that the energy transmitter(ET)in the WPT system is equipped with a constant-envelope analog beamformer,instead of a digital beamformer.Focusing on user fairness,we study a minimum received power maximization problem by jointly optimizing the ET beamforming and the RIS phase shifts,subject to the constant-envelope constraints.We iteratively solve this non-convex maxmin problem by leveraging both the successive convex approximation(SCA)method and the alternating direction method of multipliers(ADMM)algorithm.Numerical results demonstrate the effectiveness of the proposed algorithm and show attractive performance gain brought by RISs.

关 键 词：reconfigurable intelligent surface wireless power transfer max-min fairness constantenvelope beamforming 

分 类 号：TM724[电气工程—电力系统及自动化]