中继选择NOMA无线系统的物理层安全

Physical layer security of relay selection NOMA wireless systems

针对解码转发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,以及在多窃听者场景下PLS性能恶化的问题,提出了一种采用修改转发(modify-and-forward,MF)协议的多中继选择NOMA无线系统PLS模型。利用高斯-切比雪夫正交定理推导了非合谋或合谋窃听场景下多中继选择MF-NOMA无线系统的安全中断概率和渐近安全中断概率的近似表达式。仿真结果验证了多中继选择MF-NOMA无线系统PLS性能分析的准确性。结果同时也表明中继数目越多或窃听者数目越少,多中继选择MF-NOMA无线系统的PLS性能越好;合谋窃听比非合谋窃听更不利于多中继MF-NOMA无线系统的安全传输。

Aiming at poor performance of physical layer security(PLS)of decode-and-forward cooperative non-orthogonal multiple access(NOMA)systems and its performance deterioration in the presence of multi-eavesdropper,the PLS model of multi-relay selection NOMA wireless systems using modify-and-forward(MF)protocol was pro‐posed.The approximate expressions of secrecy outage probability(SOP)and asymptotic SOP of multi-relay selection MF-NOMA wireless systems with non-colluding or colluding eavesdropping scenarios were derived by using Gauss-Chebyshev Quadrature theorem.The simulation results verify the accuracy of PLS performance analysis of the above MF-NOMA wireless systems.The results also indicate that the PLS performance of multi-relay selection MF-NOMA wireless systems will be improved when the number of relays increases or the number of eavesdroppers decreases,and that colluding eavesdropping is more detrimental to secure transmission of multi-relay MF-NOMA wireless sys‐tems than non-colluding eavesdropping.