Strive for the spectrum sharing by transferring energy and relaying data for the primary user

Abstract

AbstractThrough harvesting energy from the environment, the wireless system can be sustainable and work for a long time. The spectrum sharing is promising to cope with the contradiction between the shortage of spectrum and the ever‐growing transmission requirements. Jointly considering the energy and spectrum efficiencies, we proposed in this work an energy harvesting (EH)‐based spectrum sharing scheme. The cognitive radio network with one primary link and one secondary link is studied, where the primary base station (BS) serves its primary user (PU), and the secondary access point (AP) intends to communicate with a secondary user. The PU should harvest the wireless energy for the uplink data transmission, while all the other terminals have the stable power supply. The AP can wirelessly transfer energy to the PU along with the BS to improve the EH efficiency, and further, it can relay the primary data to the BS to improve the spectrum efficiency. The energy and data cooperation from the AP can significantly enhance the throughput of primary system, and hence, more spectrum can be released for the secondary data transmission. The resource allocation between the two systems for the energy transfer and data relaying is determined through maximising the throughput of secondary link while guaranteeing the performance of primary link. Under the peak power constraint, the system performance is analysed considering the dependence of the downlink energy transfer and the uplink data relaying. Numerical results are provided to reveal the impacts of various parameter settings to the system performance. Copyright © 2015 John Wiley & Sons, Ltd.