Energy-Efficient Resource Allocation in NOMA-based HCN Systems

In this paper, the energy efficient resource allocation in NOMA-based heterogeneous cellular network (HCN) systems is investigated. Since energy consumption and its limitations is one of the important challenges in fifth generation of cellular networks (5G), we propose a resource allocation problem which allocates power and subcarriers to multiple users to achieve the best system energy efficiency (EE). To solve the corresponding problem an iterative algorithm is used. In each iteration power and subcarrier are assigned separately. In each iteration, to solve the power allocation problem dual method considering successive convex approximation (SCA) approach is used, and to solve the subcarrier allocation problem, mixed integer non-linear programing (MINLP) of optimization toolboxes is applied. The effectiveness of this resource allocation method is illustrated in simulation results section.