EHLinQ: Distributed Scheduler for D2D Communication With RF Energy Harvesting

In this paper, we study distributed scheduling for a device-to-device (D2D) communication system with radio frequency energy harvesting (RF-EH) in which D2D devices can harvest energy using the ambient RF signals from other transmitting D2D devices. In the system, due to RF-EH, the effects of link scheduling for each D2D link on the system performance, i.e., average sum rate and average total harvested energy, become much more complicated compared with conventional D2D communication without RF-EH. To address such complicated effects in a distributed manner, we study a centralized optimal link scheduling algorithm, which aims at maximizing the weighted sum of average sum rate and average total harvested energy, while satisfying the quality of service (QoS) requirements of D2D links. We then abstract the scheduling principles in the optimal algorithm, and propose a distributed scheduling algorithm for D2D communication with RF-EH, EHLinQ, which realizes the principles in a distributed manner. Moreover, we extend EHLinQ to a power beacon (PB) aided D2D communication system in which a PB transmits RF signals dedicated for RF-EH. The extended EHLinQ allows the PB to determine its own PB scheduling considering the QoS satisfaction of D2D links. Through simulation results, we show that EHLinQ outperforms conventional algorithms, while closely meeting the QoS requirements.