一种基于随机几何理论的RIS辅助PD-NOMA网络物理层安全增强方法  

An Approach of Enhancing the Physical Layer Security of RIS-assisted PD-NOMA Networks Based on Stochastic Geometry

作　　者：冯琳琳 张治中 胡昊南 裴二荣[1] 李云[1] FENG Linlin;ZHANG Zhizhong;HU Haonan;PEI Errong;LI Yun(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;School of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,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]南京信息工程大学电子与信息工程学院,南京210044

出　　处：《电子与信息学报》2023年第10期3631-3639,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62001238,62071077,61901075);工业和信息化部行业专项(TC210H02P/2)。

摘　　要：为提升基于非正交多址访问(NOMA)大规模雾接入网络的上行物理层安全(PLS),该文考虑了可重构智能表面(RIS)辅助无小区(CF)传输场景。基于功率域复用NOMA(PD-NOMA)并调用随机几何工具将空间效应引入所考虑网络的RIS模型设计,基于该方法来增强其PLS。该网络采用发射机-发射机对建模、Fisher-Snedecor模型表征复合信道,并重新设计了RIS反射模型。首先推导出所考虑网络组合信道增益的新统计特性,接着推导出RIS辅助PD-NOMA传输场景保密中断概率(SOP)的解析表达式。分析结果和仿真结果表明:该RIS设计能有效提高边缘用户信道质量,从而改变该网络NOMA用户对连续干扰消除(SIC)顺序;该RIS设计及排斥性雾节点(F-AP)部署均可增强该网络PLS,其中,基于β-Ginibre点过程(β-GPP)部署F-AP,在同等条件下,不需增加部署成本即可使SOP至多降低约2个数量级、使保密速率至多提升约10.5%。The uplink Physical Layer Security(PLS)of large-scale Non-Orthogonal Multiple Access(NOMA)-based Fog access networks with a Reconfigurable Intelligent Surface(RIS)-assisted Cell-Free(CF)framework is investigated in this paper.The spatial effects of Fog-Access Point(F-AP)locations are introduced into the RIS reflecting model design by invoking stochastic geometry and Power Domain(PD)multiplexing schemes,this spatial-repulsion-based co-design approach is proposed to enhance the PLS of the considered system.This Fsystem is modeled with reference to a receiver-transmitter pair,the Fisher-Snedecor model is adopted to characterize the composite channel,and the RIS reflecting model is redesigned.The analytical expressions of the Security Outage Probability(SOP)for RIS-assisted PD-NOMA scenarios are derived following the newly expressed channel statistics of the combined channel gains.The analytical and simulation results indicate that the proposed RIS redesign is capable of enhancing the edge users’channel quality effectively to alter the Successive Interference Cancellation(SIC)orders of NOMA user pairs in this investigated network;The PLS performance of this network can be improved by the proposed RIS redesign and repulsively distributed F-AP deployment,where deploying F-APs in aβ-Ginibre Point Process(β-GPP)way can reduce a maximum of two 10.5%orders of magnitude of the SOP and increase a maximum of of the security rate without additional deployment costs under the same conditions.

关 键 词：物理层安全 可重构智能表面 非正交多址接入 随机几何 

分 类 号：TN92[电子电信—通信与信息系统]