Security and Reliability Tradeoff of NOMA Based Hybrid Satellite-Terrestrial Network With a Friendly Jammer

This paper analyzes the security and reliability tradeoff (SRT) performance for a hybrid satellite-terrestrial network (HSTN) using the non-orthogonal multiple access (NOMA) protocol. To improve the SRT performance of the NOMA based HSTN, a friendly jammer assisted transmission (FJT) scheme is proposed and its outage and intercept probability expressions are carried out in closed-form. The transmission secrecy outage probability is given to show the tradeoff between the security and reliability of the FJT scheme. For the purposes of comparison, the none jammer aided transmission (NJT) scheme is also considered in simulations. Numerical results reveal that the FJT scheme significantly enhances the SRT performance of each user and the whole system compared to the NJT scheme. Moreover, the power allocation between users and that between the relay and the friendly jammer can be adjusted to achieve better SRT performance.