Outage performance analysis of underlay cognitive DF relaying network with SWIPT in Nakagami-m fading environment

In this paper, the outage performance of underlay cognitive decode-and-forward (DF) relaying networks with simultaneous wireless information and power transfer (SWIPT) in Nakagami-m fading channel is studied. We consider the case where the secondary transmitter (S) has fixed power supply, but no energy is provided to secondary relay node (R) which harvests energy from the part of its received signal from S. It further uses the harvested energy to forward the resulting information to the secondary receiver (D). Besides, we consider that the transmit power at S and R are both constrained by the maximum interference power at the primary user and the maximum transmit power. The exact expression for the outage probability at D is obtained, and we study the effect of energy conversion efficiency, the maximum tolerable interference power constraint, the data rate and the maximum transmit power on the OP performance. Finally, Monte-Carlo simulation is provided to verify the correctness of our analysis results.