Performance Analysis of SWIPT Networks over Composite Fading Channels

This paper studies the performance of dual-hop decode-and-forward (DF) simultaneous wireless information and power transfer (SWIPT) systems over Fisher-Snedecor $\mathcal{F}$ composite fading channels. We commence by deriving closed-form expressions of the cumulative distribution function (CDF) and the probability density function (PDF) of the product of two $\mathcal{F}$ random variables. These statistics are then used to derive closed-form expressions for the ergodic capacity and ergodic outage probability of the system under consideration. Three well-known energy harvesting (EH) relaying protocols are considered; namely time-switching relaying, power splitting relaying and ideal relaying receiver. The analysis provides insights into the effect of the key parameters on the overall network performance. Monte-Carlo simulations are provided throughout to validate the correctness of our analysis. The results show that the performance of the system in terms of ergodic capacity and outage probability improves as the fading and shadowing severity reduce for all EH protocols considered. The results further demonstrate the need to balance the relay distance with channel conditions of the links to minimise the system outage.