Energy And Spectral Efficiencies Trade-Off In Mimo-Noma System Under User-Rate Fairness And Variable User Per Cluster

The power proportion allocation for each user in down-link (DL) multiple-input and multiple-output (MIMO) non-orthogonal multiple access (NOMA) systems is analyzed. Successive interference cancellation (SIC) technique is deployed to recover users' signal with highest differences between channel gains. In proposed optimization design, initially, the minimum total power and the power proportion factor for each active user are obtained. After that, the maximum system energy efficiency (EE), the equal data rate, total power and power-proportion distribution along the users and clusters are determined under a certain circuitry power consumption. Both optimization procedures have deployed the same constraints and all users were subjected to the equal data rate. The numerical results show that the total number of users reach the maximum EE in each analyzed clusters-users configurations. The number of total users in the cell for specific number of users-per-cluster (2, 3 or 4) that simultaneously maximize EE and the equal data rate per user (representing the maximum fairness) among all active MIMO-NOMA users depends on the path-loss channel coefficients, the number of users-per-cluster and the cell coverage (radius). (C) 2021 Elsevier B.V. All rights reserved.