双无线供能IRS辅助的无线通信系统的吞吐量优化研究  

Throughput optimization for wireless communication systems assisted bydual wireless powered IRS

作　　者：陈健锋 崔苗[1] 张广驰[1] Chen Jianfeng;Cui Miao;Zhang Guangchi(School of Information Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学信息工程学院,广州510006

出　　处：《计算机应用研究》2023年第10期3107-3113,共7页Application Research of Computers

基　　金：国家重点研发计划资助项目(2020YFB1805300)

摘　　要：在未来物联网等新型无线网络场景中,需要进行信息和能量同步传输,而且通信环境复杂多变,通信设备维护成本较高。一方面,智能反射面(IRS)能通过对无线信道的智能调控提高无线通信与无线传能的性能,另一方面,通过无线能量传输对IRS进行供能,解决部署IRS时存在的供能不便的问题,降低设备维护成本。研究双无线供能IRS辅助的无线通信系统的吞吐量优化,在该系统中,多天线基站先向IRS无线传输能量,然后在IRS的辅助下向多个单天线用户发送信息。针对基站与IRS之间的信道不受阻和受阻两种情况,分别提出两时隙和三时隙的传输模式,并研究优化它们的吞吐量。具体而言,研究联合优化基站的发射波束成形、IRS的反射波束成形以及各时隙长度,在基站最大发射功率、各用户最小接收速率、各时隙持续时间和IRS反射系数的模一约束下,最大化系统的总吞吐量。由于优化变量高度耦合,难以直接求最优解,提出了基于交替优化、连续凸逼近和半正定松弛的优化算法,以求得优化问题的高质量次优解。仿真结果显示,所提联合优化算法取得了明显高于基准算法的吞吐量性能,并且揭示了两时隙和三时隙传输模式的适用场景。In new wireless network scenarios,such as the future Internet of Things,it is necessary to transmit information and energy simultaneously,and the communication environment is complex and variable,with high maintenance costs for communication equipment.On the one hand,IRS can improve the performance of wireless communication and wireless power transfer by intelligent adjustment of the wireless channel.On the other hand,providing power supply to IRS by wireless power transfer can solve the problem of inconvenient power supply of IRS and reduce the maintenance costs.This paper investigated the throughput optimization of a dual wireless powered IRS-assisted wireless communication system,in which the multi-antenna base station(BS)first transmitted energy to two IRS,and then transmitted information to multiple single-antenna users with the help of the IRS.For the cases without and with channel blocking between the BS and the IRS,this paper proposed two-phase and three-phase transmission modes,respectively.It maximized the throughputs of these modes by optimizing the transmit beamforming of the BS,the reflect beamforming of the IRS,and the time allocation of different phases,subject to the constraints of the maximum transmit power of the BS,the minimum rate of the users,the duration of each phase,and the unit-module reflection coefficients of the IRS.Since the resulting optimization problems were convex and the optimization variables were highly coupled,it was difficult to find their optimal solution directly.This paper proposed two optimization algorithms based on the alternating optimization,successive convex approximation,and semi-definite relaxation techniques to obtain high-quality sub-optimal solutions.Simulation results show that the proposed algorithms achieve significantly better throughput performance compared to some benchmark algorithms and demonstrate the suitable application scenarios of the two-phase and three-phase transmission modes.

关 键 词：智能反射面 无线供能 吞吐量优化 

分 类 号：TN929.5[电子电信—通信与信息系统]