Buffer-aided cooperative spectrum sharing with full-duplex wireless-powered relay
Abstract A buffer-aided wireless energy harvesting and information transfer protocol is proposed for full-duplex cooperative cognitive radio networks. In particular, during a transmission block, a secondary transmitter (ST) as a full-duplex relay first scavenges dedicated radio frequency (RF) energy signal transmitting from primary transmitter (PT), and then assists to transmit primary signals by using the harvested energy in exchange for the opportunity of spectrum sharing, where the primary and secondary signals are combined linearly. A buffer with limited-size is implemented on the ST and secondary receiver (SR) to storage the decoded current primary data. The SR performs successive interference decoding and cancelation to obtain desired secondary signal. The primary receiver (PR) detects the desired primary signal by treating the secondary signal as interference. Based on this, the closed-form expressions of the exact outage probabilities for both the primary and secondary systems are derived. Optimal energy harvesting duration and power allocation factor are determined by maximizing the achievable throughput of secondary system while maintaining the transmission performance of the primary system. Simulation results demonstrate that the proposed scheme achieves effective primary transmission while provides a superior transmission performance for the secondary system.