Relay cooperation and outage analysis in cognitive radio networks with energy harvesting

Cooperative cognitive radio (CCR) is a novel paradigm to improve both radio spectrum efficiency and communication quality. In this paper, we consider a CCR network (CCRN) with energy harvesting in which multiple secondary transmitters (STs) are able to harvest energy from the received signals to serve their own receivers and primary transmitters (PTs). Besides, not only PT's transmitting signal but also interferers, i.e., RF signals in ambient environment received at STs can be used for energy harvesting. Moreover, we aim to analyze the outage probability (OP) for two relay cooperation schemes including single-relay cooperation (SC) and multirelay cooperation (MC) in CCRNs while considering energy harvesting. In addition, we consider Nakagami-m fading rather than Rayleigh fading channels as it is more practical and general for characterizing the fading effect over wireless channels. Most importantly, we compare the outage performance of SC and MC with that of direct transmission and investigate the tradeoff between the primary and secondary users' performance. Simulation results are presented to validate our analysis, which show the exact performance for different parameter settings.