Load Balancing and Resource Allocation in NOMA-enabled Multi-Cellular Heterogeneous Networks Using Hybrid SON Techniques

Abstract

In this paper, we consider the two prominent Self-Organizing Network (SON) functionalities, namely load balancing (LB) and resource allocation (RA), in Non-Orthogonal Multiple Access (NOMA)-enabled multi-cellular heterogeneous networks. Specifically, we propose distributed algorithms where users are handed-over from the congested tiers to provide LB, and RA is performed to minimize co-channel interference. To mitigate the effects of increased co-channel and inter-user interference, a hybrid NOMA method is also adopted. Numerical results demonstrate that the joint consideration of SON functions provides significant improvements in data rate and fairness among users. Moreover, as the number of users and base stations increases, the application of hybrid NOMA becomes more beneficial for interference coordination. Additionally, it is shown that NOMA can provide higher data rates compared to existing Orthogonal Frequency Division Multiple Access (OFDMA) schemes with proper user grouping methods.