Performance Enhancement of 5G Networks: Remodeling Power Domain Scheme Through NOMA-MIMO Technologies Integration

The integration of multiple-input multiple-output (MIMO) and non-orthogonal multiple access (NOMA) technologies addresses critical challenges such as massive connectivity, low latency, and high dependability in 5G cellular systems and beyond. However, resolving these issues required additional research, particularly in the case of 5G networks employing MIMO. This involved enhancing and reevaluating parameters like bit error rate, downlink spectrum efficiency, average capacity rate, and uplink transmission outage probability to optimize performance. The devised model utilized Quadrature Phase Shift Keying modulation on selected frequency channels, accommodating users with diverse power location coefficients, signal-to-noise ratios, transmit powers, and bandwidths. Evaluating the proposed model's effectiveness involved testing and comparing results to previous research. Download transmission results demonstrated that MIMO-NOMA significantly improved the bit error rate performance and transmitting power for the best-evaluated user. For uplink transmission, the average capacity rate was used to assess performance, indicating an increase in the average capacity rate for the best user and a decrease in outage probability. Closed-form formulas for bit error rate, spectrum efficiency, average capacity rate, and outage probability for both downlink and uplink NOMA, with and without MIMO, were derived. In essence, adopting MIMO-NOMA led to a remarkable improvement in the performance of all users, even those facing challenges such as interference or fading channels.