Analyzing SLIPT for DF Based Mixed FSO-RF Communication System

In this paper, we consider a decode-and-forward (DF) relay-assisted mixed free space optical-radio frequency (FSO-RF) system, where the FSO system utilizes simultaneous light-wave information and power transfer (SLIPT) to extend the lifetime of the system. Considering energy harvesting at DF relay node, we derive the statistics of end-to-end signal-to-noise ratio (SNR). For the considered system, the FSO channel is modeled by the Gamma-Gamma turbulence model affected by zero boresight pointing error, and the non-coherent intensity modulation with direct detection (IM/DD) technique is employed at the FSO receiver. Further, the RF channel is assumed to undergo Nakagami-m fading. In particular, analytical closed-form expression of outage probability is derived for the considered network in terms of Meijer's G-function. To obtain further insights, we derive asymptotic outage probability expression and evaluate the diversity order analytically. The impact of DC bias along with various atmospheric turbulence and misalignment conditions on the system performance is revealed for SLIPT based mixed FSO-RF communication system. Numerical results manifest that the considered DF-based mixed FSO-RF communication system utilizing SLIPT significantly outperforms the corresponding amplify-and-forward (AF) relay-based communication system. The analytical results are corroborated through Monte-Carlo simulations.