Specific Order and Bisection Search Aided Joint 3D Beamforming and RIS Reflecting Optimization  

作　　者：Hongxing He Li Li Peichang Zhang Xiaohu Tang 

机构地区：[1]School of Information Science and Technology,Southwest Jiaotong University,Chengdu 610031,China [2]College of Electronic and Information Engineering,Shenzhen University,Shenzhen 518060,China

出　　处：《China Communications》2023年第5期330-339,共10页中国通信（英文版）

基　　金：supported by the National Key R&D Program of China under Grant 2019YFB1803400;partly by National Natural Science Foundation of China under Grant 62071394.

摘　　要：In this paper,a three-node transmission model is conceived,where the base station(BS)node leverages 3D beamforming,the reconfigurable intelligent surface(RIS)node can constructively reconfigure the wireless channel,the user node only has a single antenna due to a limited price.Maximization of its downlink spectral efficiency is a joint optimization problem of three variables,namely phase-shift matrixΦof RIS,tilt angleθand beamforming vector w used in BS 3D beamforming.We solve this problem by employing the alternating optimization(AO)algorithm.But,in each iteration,a specific optimization order of firstlyΦ,secondlyθand finally w is proposed,which facilitates the search of optimalθin the way of narrowing its trust region and enabling unimodal property over the narrowed trust region.It finally results in a better combination of{Φ,θ,w}.

关 键 词：reconfigurable intelligent surface vertical beamforming joint optimization 

分 类 号：TN929.5[电子电信—通信与信息系统] TN820[电子电信—信息与通信工程]