摘要
针对解码转发(decode-and-forward,DF)协作非正交多址接入(non-orthogonal multiple access,NOMA)系统物理层安全(physical layer security,PLS)性能较差,以及实际收发信机中器件存在的硬件损伤问题,提出了一种在多窃听场景中合法、窃听用户的收发设备中均存在硬件损伤的修改转发(modify-and-forward,MF)协作NOMA系统PLS模型,并研究在发送端采用发射天线选择(transmit antenna selection,TAS)来改善在Nakagami-m衰落信道上的PLS性能。利用高斯-切比雪夫正交定理推导了采用TAS的MF-NOMA系统的安全中断概率、渐近安全中断概率和严格正安全容量的近似表达式。MF-NOMA系统的安全中断概率和严格正安全容量的数值计算结果与仿真结果一致,同时表明在相同的硬件损伤下MF-NOMA系统的PLS性能优于DF-NOMA系统;基站发射天线数越多、窃听数越少,则MF-NOMA系统的PLS性能越好;硬件损伤对MF-NOMA的PLS性能的恶化程度主要与各硬件损伤系数和各链路的平均信噪比有关,且随硬件损伤所在节点的不同而程度各异。
In the view of poor physical layer security(PLS)performance of decode-and-forward(DF)cooperative non-orthogonal multiple access(NOMA)systems and the problem of hardware impairments in actual transceiver devices,a PLS model for a modify-and-forward(MF)cooperative NOMA system was proposed.In this model,hardware impairments exist in the transmitting and receiving devices of both legitimate and eavesdropping users in a multi-eavesdropping scenario.The transmit antenna selection(TAS)technique is employed at the transmitter to improve its PLS performance over the Nakagami-m fading channel.The approximate expressions for the secure outage probability,asymptotic secure outage probability,and strictly positive secrecy capacity of the MF-NOMA system with TAS were derived by using the Gaussian-Chebyshev quadrature theorem.The numerical calculation results of the secure outage probability and strictly positive secrecy capacity of the MF-NOMA system were consistent with the simulation results.The results show that under the same hardware impairments,the PLS performance of the MF-NOMA system outperforms that of the DF-NOMA system.The more transmit antennas of the base station has,the fewer eavesdroppers exist,the better the PLS performance of MF-NOMA system is.The degree of degradation of the MF-NOMA’s PLS performance caused by hardware impairments is mainly related to each hardware impairment coefficient and the average signal-to-noise ratio of each link,and varies depending on the node where the hardware impairment is located.
作者
叶明珠
李光球
张旭
高杰
王志康
YE Mingzhu;LI Guangqiu;ZHANG Xu;GAO Jie;WANG Zhikang(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)
出处
《电信科学》
北大核心
2025年第9期69-84,共16页
Telecommunications Science
