Closed-Form Solution for Energy Efficiency Maximization in Uplink IRS-Assisted Multi-User NOMA Network

Meftah, El-Hadi (Department of Electronics, Faculty of Electrical Engineering, USTHB, Algiers, Algeria)
Benmahmoud, Slimane (Department of Electronics Engineering, Mohamed Boudiaf University, M’sila, Algeria)

Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
Vol 13, No 2: June 2025

Given the growing concerns about energy consumption and its negative impact on the ecosystem, energy efficiency (EE) has become one of the most important key performance indicators in current and future wireless communication tech nologies. In this paper, we address the EE maximization problem in an uplink intelligent reflective surface (IRS)-assisted multi-user non-orthogonal multiple access (NOMA) network. This problem is formulated as a trade-off between the spectral efficiency (SE) and total power consumption, and it appears to be non convex. To avoid the complexity associated with the traditional iteration-based Dinkelbach method, we opt for an alternative closed-form solution for the users’ transmit power based on partial derivative analysis and Lambert function. Simulation results with a realistic power consumption models confirm the accuracy of our theoretical findings.