A closed-form solution for energy-efficiency optimization in multi-user downlink NOMA

Hajar El Hassani (1) , Anne Savard (2, 3, 4) , Elena Veronica Belmega (1)

1 ETIS - UMR 8051 - Equipes Traitement de l'Information et Systèmes
2 IMT Nord Europe - Ecole nationale supérieure Mines-Télécom Lille Douai
3 CSAM - IEMN - Circuits Systèmes Applications des Micro-ondes - IEMN
4 CERI SN - IMT Nord Europe - Centre for Digital Systems

This paper investigates the energy efficiency of a multiuser downlink non-orthogonal multiple access (NOMA) system. The energy-efficiency maximization representing the tradeoff between the sum rate versus the overall power consumption is formulated as a bi-criterion optimization problem; being convex, scalarization is suitable for its solution. Assuming that each individual user has a minimum quality of service constraint, we prove that the solution of the scalarized objective can be obtained in closed form. Hence, our solution characterizes the entire Pareto-optimal boundary of the rate vs. power tradeoffs. In the special case of maximizing the ratio sum rate vs. overall power, our solution reduces the complexity of the Dinkelbach procedure to a univariate bisection method. At last, our simulation results highlight the benefit of NOMA over OMA in terms of the rate vs. power optimal tradeoff.

Mots clés: NOMA; energy efficiency; bi-criterion optimiza- tion; minimum QoS constraints

Domaines: Sciences de l'ingénieur [physics]

Hajar El Hassani, Anne Savard, Elena Veronica Belmega. A closed-form solution for energy-efficiency optimization in multi-user downlink NOMA. IEEE 31st International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2020, Aug 2020, London, United Kingdom. ⟨10.1109/PIMRC48278.2020.9217069⟩. ⟨hal-02898928⟩