Non-orthogonal multiple access in LTE heterogeneous networks with system-level evaluation

Non-orthogonal multiple access (NOMA) has been regarded as a promising technology to meet challenges in future network. NOMA based on power-domain multiplexing and successive interference cancellation (SIC) receiver is proved to be effective in enhancing system spectrum efficiency (SE). In this paper, we propose an efficient predefined user grouping and group-wise power allocation for NOMA in LTE heterogeneous networks (HetNets). For performance evaluation, we also construct a system-level simulator for LTE with NOMA based on 3GPP specifications. It is verified that the NOMA achieves higher network throughput and SE compared to the orthogonal multiple access (OMA) scheme. Besides, the performance gain by NOMA is shown to be more pronounced with an increasing number of users.