Achievable Sum Rate and Outage Probability Optimization in MIMO-NOMA FBMC/OQAM Systems

This paper introduces a novel Multiple-Input Multiple-Output Non-Orthogonal Multiple Access (MIMO-NOMA) system integrated with Filter Bank Multicarrier using Offset Quadrature Amplitude Modulation (FBMC/OQAM), designed to overcome the spectral inefficiency and limited multi-user support of conventional MIMO-Orthogonal Multiple Access (MIMO-OMA) frameworks.By synergizing the spatial diversity of MIMO, the power-domain multiplexing capabilities of NOMA, and the spectral advantages of FBMC/OQAM-such as reduced inter-carrier interference and enhanced spectral containment-the proposed system achieves significant performance gains.A rigorous mathematical model is developed to evaluate the system under Rayleigh, Rician, and Nakagami fading channels, with a focus on achievable sum rate, outage probability, and spectral efficiency.Analytical results demonstrate that the 33 MIMO-NOMA-FBMC/OQAM configuration attains an exceptional sum rate of 35 bps/Hz for near users, outperforming MIMO-OMA by 86%, while reducing outage probability for far users by 50% at high SNR regimes.The system's ability to dynamically allocate power (e.g., coefficients 0.65, 0.25, 0.1 for 33 configurations) and leverage FBMC's spectral efficiency factor (_(FBMC > 1)) ensures robust performance across heterogeneous channel conditions.Comparative studies against existing MIMO-OMA and NOMA variants highlight superior fairness, reliability, and capacity, particularly in dense multi-user environments.These findings position the proposed architecture as a pivotal enabler for future wireless networks, addressing critical demands for high throughput, low latency, and scalable connectivity in 5G/6G systems.