Secrecy Performance of RIS Aided NOMA Networks

Abstract

Reconfigurable intelligent surface (RIS) has been regarded as a promising technology since it has ability to create the favorable channel conditions. This paper investigates the secrecy performance of RIS aided non-orthogonal multiple access (NOMA) networks, where the internal eavesdropping scenario is taken into consideration. More specifically, novel closed-form and asymptotic expressions of secrecy outage probability for the k-th user are derived. According to the analytical results, the secrecy diversity orders at users are acquired in the high signal-to-noise ratio region. Simulation results show that the applying of RIS in NOMA networks can remarkably improve the performance of secrecy outage behaviour and secrecy system throughput compared to RIS aided orthogonal multiple access networks.