Comparative Performance Analysis of Orthogonal and Non-Orthogonal Multiple Access Schemes in 5G Systems

Abstract: This paper presents a comparative performance analysis of Orthogonal Multiple Access (OMA) and Non- Orthogonal Multiple Access (NOMA) techniques for 5G wireless communication systems. The OMA performance is modelled using OFDM and MIMO-OFDM under single-user and multi-user scenarios, while NOMA is implemented as a two-user power-domain system with Successive Interference Cancellation (SIC). Bit Error Rate (BER) and system throughput (sum rate) are evaluated through MATLAB-based simulations against varying levels of transmit power under identical channel conditions. The results reveal that although OMA schemes provide simpler implementation and effective interference management, NOMA achieves significantly higher sum rate while maintaining acceptable BER performance, especially at higher transmit power levels. These findings underscore NOMA’s potential to meet the growing spectral efficiency and user connectivity requirements of future 5G networks.

Keywords: OMA, NOMA, OFDM, MIMO-OFDM, Bit Error Rate (BER), Sum Rate, Transmit Power, 5G, Spectral Efficiency, SIC (Successive Interference Cancellation)