Outage performance of multi cell-NOMA network over Rician/Rayleigh faded channels in interference limited scenario

Non-orthogonal multiple access (NOMA) is a promising methodology for future wireless communications which provide an extra domain to access the channel. This paper evaluates the outage performance of multi-cell NOMA network in interference limited scenario. To asses the outage probability, initially we observed interference from the adjacent cells and later considered the channel propagation affect. It is assumed that, the required signal undergoes Rician fading and the interfering signals experience Rayleigh fading channel. The closed-form expressions are obtained for the outage probability of NOMA over Rician/Rayleigh faded channel including imperfect-channel state information (CSI) and successive interference cancellation (SIC). The obtained expressions are used to evaluate the outage probability of NOMA with random number of interferers with different values of offered load (Erlangs per cell). We calculate the outage probability for three users in a hexagonal cell such as near user, middle and edge user. The derived expressions help in assessing the impact of interference and imperfect-CSI and SIC on the outage performance of NOMA in different fading scenarios. The obtained results, when compared with the simulated NOMA are very appreciable.