Practical Non-Linear Responsivity Model and Outage Analysis for SLIPT/RF Networks

Simultaneous lightwave information and power transfer (SLIPT) is considered as an effective method of transferring information and energy via illuminated lightwaves. In this paper, we investigate the effect of non-linear responsivity on the SLIPT/radio frequency (RF) performance. We develop a tractable mathematical model for the non-linearity of responsivity and use it to study the end-to-end signal-to-interference-plus-noise ratio (SINR). Based on that, we derive the closed-form expressions for the probability density function and cumulative distribution function of the output SINR at the receiver. These statistical distributions are then used to derive the closed-form expressions of the outage probability of SLIPT/RF system over Nakagami-$m$ fading channels. Numerical results indicate that the simplified model used in previous studies leads to inaccurate performance evaluation results, and that our model provides more accurate evaluation. We also verify the analytical findings by simulation.