Physical Layer Security Performance Analysis of the FD-Based NOMA-VC System

In this paper, we consider the secrecy outage probability (SOP) of a cooperative non-orthogonal multiple access (NOMA) vehicular communication (VC) system, where the relay is working in either half-duplex (HD) or full-duplex (FD) mode. We assume that all these links experience Nakagami-m fading. Some closed-form analytical expressions for the SOP performance of the FD/HD cooperative NOMA-VC system are derived. Results show that the secrecy performance of FD-based NOMA-VC system is superior than HD-based NOMA-VC in the low signal noise ratio (SNR) region, and can be further improved by reducing the self-interference caused by FD technique. Finally, the validity of this analytical expressions is verified by using simulation. The simulation results show that the simulation curve can be fit well with our analytical results.