Secrecy Rate Analysis for RIS-Aided Multi-User MISO System over Rician Fading Channel  

作　　者：Jiaping Wang Jun Zhang Jiacheng Lu Jue Wang Qi Zhang Dongqian Wang 

机构地区：[1]School of Communication and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210000,China [2]School of Information Science and Technology,Nantong University,Nantong 226019,China.

出　　处：《Journal of Communications and Information Networks》2023年第1期48-56,共9页通信与信息网络学报（英文）

基　　金：the National Natural Science Foundation of China.92067201;the National Natural Science Foundation of China.62071247;the National Natural Science Foundation of China.62171240;the National Natural Science Foundation of China.62171231;Jiangsu Provincial Key Research and Development Program.BE2020084-4

摘　　要：The reconfigurable intelligent surface(RIS),which is composed of multiple passive reflective components,is now considered as an effective mean to improve security performance in wireless communications,as it can enhance the signal of legitimate users and suppress the power leakage at eavesdroppers by adjusting signal phases.In this paper,we maximize the downlink ergodic secrecy sum rate of a RIS-aided multi-user system over Rician fading channels,where we assume that only imperfect channel state information(CSI)is available at the base station(BS).Firstly,we obtain the deterministic approximate expression for the ergodic secrecy sum rate by resorting to the large-system approximation theory.Then the problem is formulated to maximize the downlink ergodic secrecy sum rate by optimizing the regularization coefficient of regularized zero-forcing(RZF)precoding and the phase-shifting matrix of the RIS.By using the particle swarm optimization(PSO)method,we propose an alternate optimization(AO)algorithm to solve this non-convex problem.Finally,the numerical simulations illustrate the accuracy of our large-system approximate expression as well as the effectiveness of the proposed algorithm.

关 键 词：RIS large-system approximation RZF precoding imperfect CSI ergodic secrecy sum rate 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]