智能反射面辅助无线网络性能及最优位置分析  

Performance and Optimal Placement Analysis of Intelligent Reflecting Surface-assisted Wireless Networks

作　　者：束锋 赖斯豪[1] 刘川 高炜 董榕恩 王艳 SHU Feng;LAI Sihao;LIU Chuan;GAO Wei;DONG Rongen;WANG Yan(School of Information and Communication Engineering,Hainan University,Haikou 570228,China;School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;State Grid Smart Grid Research Institute Co.,Ltd.,Beijing 102209,China)

机构地区：[1]海南大学信息与通信工程学院,海口570228 [2]南京理工大学电子工程与光电技术学院,南京210094 [3]国网智能电网研究院有限公司,北京102209

出　　处：《电子与信息学报》2025年第2期324-333,共10页Journal of Electronics & Information Technology

基　　金：国家重点研发计划(2023YFF0612900);国家自然科学基金(U22A2002,62071234);海南省科技专项基金(ZDKJ2021022);海南大学科研启动项目(KYQD(ZR)-21008);海南大学信息技术协同创新中心项目(XTCX2022XXC07)。

摘　　要：当基站(BS)和用户的位置固定,基站到智能反射面(IRS)与IRS到用户的距离和一定时,该文在视距信道和瑞利信道下基于最大化系统可达速率准则对无源和有源IRS的最优放置位置进行分析。首先,运用相位对齐和大数定律推导了无源和有源IRS辅助无线网络可达速率的闭合表达式;然后,分析了基站到IRS的路径损耗指数β_(1)和IRS到用户的路径损耗指数β_(2)对IRS最优部署位置的影响,即当β_(1)>β_(2)时,无源IRS的最优部署位置始终靠近基站,随着β_(1)和β_(2)的差距逐渐增大,有源IRS的最优部署位置逐渐靠近基站;当β_(1)<β_(2)时,则得到相反的结论。仿真结果表明:当β_(1)=β_(2)且无源IRS到基站和到用户的距离相等时,系统的可达速率性能最差。当固定有源IRS处的噪声功率且增加用户处的噪声功率时,IRS的最优部署位置始终靠近用户;当固定后者增大前者时,IRS的最优部署位置逐渐靠近基站。Objective:Previous studies have extensively examined the performance of Intelligent Reflecting Surface(IRS)-assisted wireless communications by varying the location of the IRS.However,relocating the IRS alters the sum of the distances between the IRS and the base station,as well as the distances to users,leading to discrepancies in reflective channel transmission distances,which introduces a degree of unfairness.Additionally,the assumption that the path loss indices for the base station-to-IRS and IRS-to-user channels are equal is overly idealistic.In practical scenarios,the user's height is typically much lower than that of the base station,and the IRS may be positioned closer to either the base station or the user.This disparity results in significantly different path loss indices for the two channels.Consequently,this paper focuses on identifying the optimal deployment location of the IRS while keeping the total distance fixed.The IRS is modeled to move along an ellipsoid or ellipsoidal plane defined by the base station and the user as focal points.The analysis provides insights into the optimal deployment of the IRS while taking into account a broader range of application scenarios,specifically addressing different path loss indices for the base station-to-IRS and IRS-touser channels given a predetermined sum of the transmitting powers.Methods:Utilizing concepts of phase alignment and the law of large numbers,closed-form expressions for the reachability rate of both passive and active IRS-assisted wireless networks are initially derived for two scenarios:the line-of-sight channel and the Rayleigh channel.Following this,the study analyzes how the path loss exponents from the base station to the IRS and from the IRS to the user impact the optimal deployment location of the IRS.Results and Discussions:The reachability rate of a passive IRS-assisted wireless network,considering IRS locations under both line-of-sight and Rayleigh channels,is illustrated.It is evident that the optimal deployment location of the IRS

关 键 词：智能反射面 大数定律 智能反射面最优位置 可达速率 

分 类 号：TN92[电子电信—通信与信息系统]