Ding, MAtapattu, SWeeraddana, CEvans, J2022-06-202022-06-202021-03M. Ding, S. Atapattu, C. Weeraddana and J. Evans, "Energy-Efficiency Fairness of Interference Multi-Relay Networks for Multi-User Communications," in IEEE Communications Letters, vol. 25, no. 3, pp. 955-959, March 2021, doi: 10.1109/LCOMM.2020.3041210.1089-7798https://rda.sliit.lk/handle/123456789/2638We investigate a single-antenna multi-user multi-relay interference network, where multiple source nodes simultaneously communicate with their respective destination nodes via half-duplex decode-and-forward relays. To ensure fairness among users, we consider a power allocation strategy to maximize the worst-case energy efficiency (EE) of all users for a fixed relay assignment. The resulting optimization problem turns out to be non-convex. Different from those in the literature, our method here is an iterative algorithm where two geometric programs (GPs) are solved in each iteration, one producing an upper-bound to the solution of the original problem and the other providing a feasible lower-bound. Moreover, the upper-bound GP approaches the original problem asymptotically. Our algorithm also works for the problem arising in the non-interfering (orthogonal) transmission, which was previously solved as a fractional program. Numerical results reveal that non-orthogonal transmission outperforms orthogonal transmission in terms of the worst-case EE at low and medium signal-to-noise ratios.enEnergy-EfficiencyFairnessInterferenceMulti-Relay NetworksMulti-UserCommunicationsArticle10.1109/LCOMM.2020.3041210