Performance Analysis of Bit Error Rate, Capacity and Outage Probability using Power Domain Non-Orthogonal Multiple Access (PD-NOMA) and Orthogonal Multiple Access (OMA) with Far/Near User

Since the first generation of cellular networks, several multiple access techniques have been researched for the next generation, and numerous emerging multiplexing/multiple access techniques are currently being investigated for the next generation. Unlike previous OMA (Orthogonal Multiple Access) systems, NOMA (Non-Orthogonal Multiple Access) technique allows a higher number of users to use the same time and frequency resource blocks, making it one of the most promising alternative strategies for 5G wireless communication. In contrast to OMA, NOMA separates power levels to increase user count, spectral efficiency, and bit error rate. A NOMA system model is assumed for the two-user scenario, as well as a Rayleigh fading channel between the transmitter and receiver with AWGN noise. SNR and data rates are computed using Rayleigh channel coefficients. In terms of channel capacity, outage probability simulation findings show that PD-NOMA with fixed power allocation outperforms OMA.