非完美CSI条件下IRS辅助的NOMA系统安全速率最大化算法  

Security rate maximization algorithm for IRS assisted NOMA systems under imperfect CSI

作　　者：王正强 何鲁娜 樊自甫[1] 万晓榆[1] 徐勇军[1] 多滨 Zhengqiang WANG;Luna HE;Zifu FAN;Xiaoyu WAN;Yongjun XU;Bin DUO(School of Communications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;College of Computer Science and Cyber Security,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065 [2]成都理工大学计算机与网络安全学院,成都610059

出　　处：《中国科学：信息科学》2024年第6期1487-1501,共15页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:U23A20279,62271094);重庆市自然科学基金创新发展联合基金重点项目(批准号:CSTB2022NSCQLZX0009);重庆市教委科学技术研究项目(批准号:KJZD-K202200601);四川省区域创新合作项目(批准号:2022YFQ0017)资助。

摘　　要：本文针对智能反射面(intelligent reflecting surface,IRS)辅助的非正交多址接入系统的物理层安全问题,考虑窃听信道为非完美信道状态信息,基站在IRS的辅助下给合法用户传输数据.在基站最大发射功率、IRS相移和连续干扰消除解码顺序约束下,建立了一个联合优化基站波束形成向量、IRS相移的系统安全速率最大化问题.首先,基于合法用户的组合信道增益来确定连续干扰消除解码顺序,然后将优化问题解耦为两个子问题交替优化,利用基于惩罚的连续凸逼近、松弛变量、一阶泰勒展开等方法将目标函数和约束进行转化,再利用S-procedure方法处理窃听信道的不确定性,将子问题转化为凸优化问题并求解.仿真结果表明,本文所提方案与集中部署IRS、随机相移、无IRS方案对比,能够有效提高系统的安全速率.This paper focuses on the physical layer security of intelligent reflecting surface(IRS)assisted nonorthogonal multiple access technology systems,considering that the eavesdropping channel is imperfect,and the base station transmits data to legitimate users with the assistance of IRS.Under the constraints of maximum transmit power of the base station,the phase shift of the IRS and successive interference cancellation(SIC)decoding order,the security rate maximization problem for the systems is formulated by jointly optimizing the beamforming vector of the base station and the phase shift of the IRS.Firstly,SIC decoding order is determined based on the combined channel gain of legitimate users.Then,the optimization problem is decoupled into two sub-problems by using an alternating optimization approach,and the objective function and constraints are transformed by exploiting penalty based successive convex approximation,relaxation variables,and first-order Taylor expansion.Next,the S-procedure method is used to deal with the uncertainty of the eavesdropping channel,and the sub-problem is transformed into a convex optimization problem and solved.Simulation results show that the proposed scheme can effectively improve the security rate of the system compared with the schemes of centralized deployment of IRS,random phase shift,and without IRS.

关 键 词：智能反射面 非正交多址接入 物理层安全 非完美信道状态信息 波束成形 

分 类 号：TN929.5[电子电信—通信与信息系统]