Wireless Power Transfer Based Spectrum Leasing with User Selection in Cognitive Radio Networks

In this paper, we propose an energy harvesting (EH) based spectrum leasing protocol in the cognitive radio network, where multiple secondary transmitters (STs) can simultaneously harvest the radio frequency energy from the primary user (PU) transmission. After the EH period, the PU transmits its data with the assistance from the STs. Among all the STs that can correctly decode the primary data and harvest enough energy, the one with the best channel status towards the primary receiver is selected to relay the primary data. Thanks to the STs' cooperation, the primary data can be more easily delivered using less time, and as a reward, all the STs except the selected one can transmit their own data in the TDMA manner. The data success probabilities of both primary and secondary systems are analyzed by considering the EH and information decoding statuses of STs. Numerical results show that our protocol can well accommodate the STs' transmissions while guaranteeing the PU performance.