The Journal of China Universities of Posts and Telecommunications ›› 2020, Vol. 27 ›› Issue (3): 62-72.doi: 10.19682/j.cnki.1005-8885.2020.0017

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Power allocation scheme for maximizing spectrum efficiency and energy efficiency tradeoff for multi-cluster NOMA system

  

  • Received:2020-01-03 Revised:2020-04-21 Online:2020-06-24 Published:2020-08-30
  • Contact: Xin-Ji TIAN E-mail:tian215216@sohu.com

Abstract: In this paper, a power allocation to maximize tradeoff between spectrum efficiency (SE) and energy efficiency (EE) is considered for the downlink non-orthogonal multiple access (NOMA) system with arbitrarily clusters and arbitrarily users, where the subcarriers of clusters are mutually orthogonal to each other. Specifically, an optimization problem of maximizing SE-EE tradeoff is formulated by optimizing power allocation among users under the constraints of user rate requirements. Then, the optimization problem is decomposed into a group of sub-problems with the aim of maximizing SE-EE tradeoff for each cluster, which is solved by using bisection method and monotonicity of function. Finally, the power allocation optimization problem among users is transformed into that between clusters, and a two steps inter-cluster power allocation algorithm is developed to solve this problem. Simulation results show that SE-EE tradeoff of the proposed scheme is better than that of the existing schemes.

Key words: NOMA, power allocation, spectrum efficiency, energy efficiency, tradeoff