Energy-Spectral Efficiency Tradeoff of Downlink NOMA System with Fairness Consideration

Abstract

In this paper, we explore the energy efficiency (EE) and spectral efficiency (SE) tradeoff with α-fairness consideration for downlink non-orthogonal multiple access (NOMA) networks based on a multi-objective optimization problem. To acquire the Pareto optimal solution of the original optimization problem, the weighted sum method is adopted to transfer the multi- objective optimization problem to a single-objective optimization problem. The trade-off between SE and EE with fairness considered can be captured through the Pareto optimal solution. Simulation results reveal the achievable SE and EE with same α of NOMA networks outperform that of OFDMA protocol as α is small, and the NOMA networks with more multiplexed users have better performance in EE and SE of NOMA networks as the fairness level among users is higher.