Multi-Relay Non-Orthogonal Multiple Access Network with Cache-Enabled Users

Abstract

This paper investigates the multi-relay non-orthogonal multiple access (NOMA) networks with cache-enabled users, in which the source transmits superimposed signals to two users, assisted by $N$ relays. We firstly analyze traditional cooperative-NOMA networks, and then discuss the cooperative-NOMA networks with cache-enabled users. Moreover, the analytical expression of outage probability for the proposed network is derived, as well as the asymptotic expression. According to the asymptotic outage probability, we obtain that the diversity order is equal to the amount of relays $N$. Furthermore, increasing the file hit probability can enhance the transmission performance of the system. Finally, numerical as well as simulation results are presented to validate our analysis.