Accurate uplink spectral efficiency for non orthogonal multiple access in Nakagami fading

In this paper, an original analysis on the uplink spectral efficiency of non-orthogonal multiple access (NOMA) in Nakagami fading channel is introduced. Based on our exact evaluation, a closed-form expression of the spectral efficiency is proposed. Distinguished from the literature, the proposed expression yields accurate numerical results, validated by the Monte Carlo simulation, of the spectral efficiency when the randomness of channel gains and number of active users are taken into account.