Power‐Allocation Algorithm for Fairness Maximisation of Non‐Orthogonal Multiple Access‐Based Multibeam Satellite Networks

ABSTRACT 5G networks and beyond set a critical requirement for both massive capacity and seamless connectivity to all users. This implies that, the network must have both very high capacity and users' fairness. Non‐Orthogonal Multiple‐Access (NOMA)‐based Multibeam Satellite Networks (MBSNs) are designed for 5G networks, and are thus, required to provide both high capacity and high users' fairness. Most existing power‐allocation (PA) algorithms for NOMA‐MBSNs focus on maximising the network's throughput alone, with not much attention on user's fairness. This leaves a critical requirement of 5G networks unaddressed. As an attempt to close this gap, this paper, proposes a PA algorithm that maximises the users' fairness of a 2Users NOMA‐MBSN. To do so, the maximisation request is formulated as an optimisation problem. The original problem being NP‐hard, it is decomposed into two sub‐problems; namely, the intra‐beam and the inter‐beam fairness maximisation. Each of these problem is independently solved by means of numerical search methods. In this regards, the concept of converging the Offered‐Capacity to Traffic‐Request (OCTR) ratios of respective users, in order to maximise the system's fairness, is employed. Thus, based on the OCTR‐ratios convergence concept, the fairness maximisations power‐allocation algorithms, which respectively solve the two sub‐problems, are designed. The two algorithms include the intra‐beam and the inter‐beam power‐allocation algorithms. A global power‐allocation algorithm (PAA‐1) combines the two algorithm, to yield a solution to the original problem. Numerical results confirm that, the algorithm makes all the OCTR‐ratios of all user converge; thus maximising the network's users‐fairness. Results also demonstrate the superiority of the proposed PAA‐1 with respect to achieved system's fairness, compared to some other existing PA algorithms.