Joint Impacts of Non-Ideal System Limitations on the Performance of NOMA-Based SatCom Networks

With the increasing shortage of satellite spectrum resources, non-orthogonal multiple access (NOMA) scheme is applied to satellite communication (SatCom) networks, which is regarded as one of the key technologies to improve spectrum efficiency. In this paper, we investigate the joint impact of non-ideal limitations, i.e., channel estimation errors, co-channel interference and imperfect successive interference cancellation on the performance of NOMA-based SatCom networks. To evaluate the performance improvement under practical scenarios, we obtain a closed-form expression for the outage probability (OP) in the presence of non-ideal limitations. To investigate the effect of non-ideal factors at high signal-to-noise ratios, an asymptotic analysis for the OP is also presented. Besides, an optimal power allocation scheme based on the non-ideal limitations is proposed to minimize the OP of the system. Finally, Monte Carlo simulations corroborate the correctness of the presented theoretical results.