硬件损伤下多窃听器NOMA系统平均保密容量分析OACSTPCD

This paper studies the physical layer security performance of non-orthogonal-multiple-access(NOMA)communication system.When the base station incorporates the down-link NOMA scheme to send information,due to the openness of the channel,the information is easy to be eavesdropped,and when there are multiple randomly distributed eavesdroppers,the security performance will be further reduced.In order to enhance physical layer security performance of the system with hardware impairments,we take the method named Protected Zone into account.Based on the characteristics of the direct link between ground users and base station,we apply the Rician fading to model small-scale fading.We also assume the locations of multiple eavesdroppers follow homogeneous Poisson point process(HPPP).The closed-form expressions of average secrecy capacity are derived with the help of Gaussian-Chebyshev quadrature,and the asymptotic expressions are also provided for obtaining the insight under high signal-to-noise-ratio cases.The simulation results verify the effectiveness of the protected zone method for enhancing the security performance,and also illustrate the impact of different parameters on the secrecy performance of the system.