Outage Analysis of Downlink Non-Orthogonal Multiple Access Scheme Over Rician Fading Channel

Non-orthogonal multiple access (NOMA) serves as a promising technology for 5G and beyond when compared to orthogonal multiple access (OMA) techniques. In order to exploit the pros of NOMA, it is vital to identify its performance over various fading channels. In this paper, the performance measures of downlink NOMA systems over different fading channels are analyzed. In particular, outage probability expression for a two-user NOMA scheme under Rician and Rayleigh fading channels are obtained. The analytical expressions are validated through simulations for both fading channels. The effect of outage probability is also observed by varying the target rates of the users. The simulation results casts that the Rician fading channel has less outage probability than Rayleigh fading channel due to the line of sight component.