Outage probability of NOMA systems with receive antenna selection in [formula omitted]-[formula omitted] fading channels

Abstract

This article considers power-domain non-orthogonal multiple access (NOMA) for downlink communication systems that involve multiple users. The base station, equipped with a single transmit antenna, communicates simultaneously with multiple users, each equipped with a single receive antenna. The article examines the system’s outage probability (OP) performance in α−μ generalized fading channels. The article first derives the instantaneous signal-to-interference-and-noise ratio (SINR) and then obtains the OP expression for each user in a closed form. The derived expression for OP is general and includes special cases such as Nakagami-m, Weibull, Gamma, Rayleigh, and Exponential distributions. This α−μ expression helps quantify the improvement of the OP performance. In order to improve the OP performance, multiple antennas are included for the users, and then receive antenna selection (RAS) scheme is employed. Finally, the theoretical OP expressions are verified via Monte Carlo simulations.