Massive MIMO and NOMA for 6G Wireless Networks: Key Technologies, Challenges, and Prospects

Abstract

Wireless access technology is a key area of research since 6G wireless networks are anticipated to enable immersive communication, enormous IoT, intelligent sensing, and ubiquitous coverage. Utilizing the method of literature review, this paper examines Massive Multiple-Input Multiple-Output (Massive MIMO) and Non-Orthogonal Multiple Access (NOMA) as two complementary access technologies for 6G wireless networks and compares their roles in the spatial and power domains. The review finds that Massive MIMO improves spectrum efficiency, system capacity, and link reliability through large antenna arrays, beamforming, and spatial multiplexing, while NOMA increases access density and edge-user fairness through power-domain multiplexing and successive interference cancellation. Their convergence can better support high-capacity 6G access, but it also introduces asynchronous interference, channel state information overhead, and high-frequency coherence challenges. By connecting these challenges with Radio Access Network digital twins, AI-assisted scheduling, and integrated sensing and communication, the paper clarifies a practical research path for Massive MIMO-NOMA convergence in future 6G networks.