Secrecy Performance Analysis of NOMA-Based Integrated Satellite-Terrestrial Relay Networks with Multiple Colluding Eavesdroppers

Abstract

This paper studies the secrecy performance of non-orthogonal multiple access (NOMA)-based integrated satellite-terrestrial relay networks (ISTRNs), where colluding eavesdropping case is considered, namely, the eavesdroppers cooperate with each other to overhear the legitimate information. Specially, we derive the closed-form expression for the secrecy outage probability (SOP) of the considered NOMA-based ISTRNs in the presence of colluding eavesdropping case. In order to obtain further insights at high signal-to-noise ratios (SNRs), the asymptotic expression for the SOP is also given, which provide an efficient mean to evaluate the benefit of NOMA scheme and the impact of colluding eavesdropping on the SOP. Moreover, we obtain the analytical results for the secrecy energy efficiency (SEE) of the considered system. Finally, numerical Monte Carlo (MC) results are given to verify the correctness of the theoretical results.