Joint Power Allocation and Rate Control for NOMA-Based Space Information Networks

In this paper, we propose a novel power allocation scheme of downlink non-orthogonal multiple access (NOMA) system for space information networks (SINs). Since the communication resources such as power and storage on satellites are limited, we focus on an optimization policy of long-term resource allocation to meet these practical constraints. To address this problem, we convert the long-term optimization problem into a series of online power allocation and rate control problems by leveraging the Lyapunov optimization framework. Then, we employ the particle swarm optimization (PSO) algorithm to derive a globally optimal solution for this joint optimization problem, with a linear computational complexity. Simulation results show that the proposed joint optimization allocation NOMA scheme for SIN can outperform OMA and multiple sub-optimal NOMA benchmark schemes, in terms of long-term network utility, average arriving rate and queuing delay.