Energy-efficient resource allocation for D2D communications in cellular networks

This paper studies resource allocation for the device-to-device (D2D) underlying cellular system where we aim to maximize two different energy-efficiency metrics of D2D links while guaranteeing the minimum data rates for cellular links. Specifically, we formulate two resource allocation problems that optimize two different objective functions corresponding to System Energy-Efficiency (SEE) and Total Individual Energy-Efficiency (TIEE). To solve these problems, we propose elegant algorithms, which decompose the considered problems into power control and cellular-D2D matching sub-problems. We prove that our proposed iterative algorithms for the SEE and TIEE problems converge to their optimal solutions. Numerical results show that the energy-efficiency achieved by the proposed SEE and TIEE algorithms is much higher than that of the optimal spectrum-efficiency (SE) algorithm with slight degradation in the system sum rate.