Performance Analysis of Energy Harvesting in Cognitive Radio Networks over Nakagami-m fading Channels

Point-to-point communication systems in wireless networks capable of energy harvesting is investigated. The relay or sensor nodes in wireless cooperative or sensor networks may require external charging mechanisms due to limited battery reserves, in order to remain active in the network. Therefore, to enable incessant relay of information, energy harvesting becomes particularly imperative in such networks. We have investigated the performance of a typical Cognitive Radio (CR) network. It is assumed that a CR node can perform the process of energy harvesting from RF signal and simultaneously sensing the spectrum via energy splitting device. Throughout the work, it is assumed that CR harvests energy from the primary user (PU) signal itself. We have captured a dynamic model of PU's behaviour with response to the re-appear and disappear probabilities by monitoring its impact on the net harvested energy as well as performance of CR. The discussed model demonstrates the expressions for harvested energy and the average throughput through analytical techniques. We have derived the relation for optimum sensing time to attain the required detection probability in the channel. The performance of considered system model is analysed in terms of outage probability and excess energy left for further transmission while considering the collision factor in PU.