Energy-Efficient Transmission Design for Downlink Non-Orthogonal Multiple Access Network

In order to improve the energy efficiency (EE) of non-orthogonal multiple access (NOMA) network, this paper focuses on energy-efficient transmission design for downlink NOMA network by reasonable resource allocation. We first study the power allocation on multiple users in each cluster and obtain the optimal closed-form solution of the power allocation coefficient. Then, a novel power allocation strategy across clusters is proposed to further maximize the total EE. Since the original optimization problem is non-convex, a successive convex approximation (SCA) method is introduced to find a sub-optimal solution of the non-convex one. Numerical results indicate that NOMA performs well than orthogonal multiple access (OMA) in terms of total EE and our proposed power allocation algorithm significantly outperforms the equal power allocation strategy.