Energy-Efficient Resource Allocation for WPT-Based D2D Communication Underlaying Cellular Network

Recently, researchers have paid much attention to Wireless Power Transfer-based Device-to-Device (D2D) Communication underlaying Cellular Network (WPT-DCCN), which has reliable and controllable energy resource, high energy and spectral efficiency. However, the Energy Efficiency (EE) of the whole WPT-DCCN which combines the time allocation and the power control of all users (including base station, cellular and D2D user), is rarely studied. Consequently, this article establishes an EE optimization model of the whole WPT-DCCN. To effectively get an optimal solution, the EE problem is equivalently converted to an Energy Consumption (EC) minimization problem and is addressed by a proposed Two-Step Iteration Algorithm (TSIA). Simulation shows that the proposed TSIA can give a tight lower-bounded solution of the optimal one. Furthermore, the results also show that whether the WPT from base station to support D2D communication is always energy-efficient, which can give us a clear reference about the deployment of future WPT-DCCN.