A Comparative Study of OMA and NOMA in 5G Networks, Analyzing Performance and Optimizing Wireless Network Capacity using NOMA

The expanding need for high-speed and dependable wireless communication systems has led to the exploration of innovative multiple-access strategies. This paper presents a comprehensive performance comparison between Non-Orthogonal Multiple Access (NOMA) and traditional Orthogonal Multiple Access (OMA) techniques. NOMA is a promising technology that allows numerous users to access identical time-frequency resources at varying power extents, achieving higher spectral efficiency and accommodating more users compared to OMA. Additionally, this paper provides a mathematical model of the NOMA approach in a fixed-cell downlink (DL) configuration with a sole base station (BS), two subscribers, and a single antenna system shared by all terminals. The research methodology involves the development of MATLAB-based simulations to evaluate the viability of both NOMA and OMA under various scenarios. The performance metrics considered include sum rate (SR), individual user rate, outage probability, and system capacity. The key objective of this study is to recognize whether NOMA can increase wireless network capacity and perform better compared to OMA. We also evaluate the influence of imperfect Successive interference cancellation (SIC) on the attainable data rate of two-user NOMA.