Energy-Efficient Power Control and Resource Allocation for D2D Communications in Underlaying Cellular Networks

In this paper, we investigate the energy-efficient power control and resource allocation problem in the context of underlaying device-to-device (D2D) communication, which aims to maximize the energy efficiency (EE) of D2D users with power and subchannel optimized while providing the quality of service (QoS) provisioning of the cellular users. We formulate it as a non-convex optimization problem in fractional form and transform it from power of all users to the joint power and subchannel allocation of D2D users. By the properties of fractional programming, we then transfer it into subtractive form and propose an energy-efficient iterative algorithm. To optimize the power and subchannel, we divide the subchannel allocation into two cases, which could be solved by penalty function approach and dual decomposition as well as sub-gradient method respectively. Accordingly, we propose a dual-based algorithm. Numerical results demonstrate that the proposed algorithms outperform a conventional algorithm in terms of energy efficiency.