Performance analysis of NOMA systems over Rayleigh fading channels with successiveinterference cancellation

Abstract

In this study, non-orthogonal multiple access (NOMA) is considered for multiusers wireless communications overRayleigh fading channel. The base station (BS) utilises NOMA technique to secure connectivity, users fairness and high spectralefficiency for multiusers with different channel conditions. Moreover, a power allocation mechanism is applied at the BS bygiving each user its required power allocation factor (PAF) in order to share the available power. Therefore, this technique allowsthe users of interest to communicate with the BS over the same frequency band simultaneously in the power domain. Moreover,successive interference cancellation is applied for users with the lower PAF to remove the strong signal of the other users.Furthermore, exact expressions are derived for different performance metrics, and the probability density function of the signalto-interference-plus-noise ratio is derived at each terminal and then exploited to obtain the outage probability and the probabilityof error. The performance analysis is verified via Monte-Carlo simulations demonstrating closed-match with theoretical analysis.