SWIPT with Practical Modulation and RF Energy Harvesting Sensitivity

TL;DR

This paper analyzes SWIPT performance with practical modulation and RF energy harvesting sensitivity, deriving tradeoffs and optimal strategies for power-splitting and time-switching schemes in Nakagami-m fading channels.

Contribution

It provides a comprehensive analysis of SWIPT with practical modulation and RF sensitivity, including optimization of energy and information transfer tradeoffs.

Findings

High peak-to-average power ratio modulations improve energy harvesting in PS scheme

Concentrating power transfer minimizes non-harvested energy in TS scheme

Channel fading enhances energy harvesting performance

Abstract

In this paper, we investigate the performance of simultaneous wireless information and power transfer (SWIPT) in a point-to-point system, adopting practical $M$-ary modulation. We take into account the fact that the receiver's radio-frequency (RF) energy harvesting circuit can only harvest energy when the received signal power is greater than a certain sensitivity level. For both power-splitting (PS) and time-switching (TS) schemes, we derive the energy harvesting performance as well as the information decoding performance for the Nakagami-$m$ fading channel. We also analyze the performance tradeoff between energy harvesting and information decoding by studying an optimization problem, which maximizes the information decoding performance and satisfies a constraint on the minimum harvested energy. Our analysis shows that (i) for the PS scheme, modulations with high peak-to-average power ratio achieve better energy harvesting performance, (ii) for the TS scheme, it is desirable to concentrate the power for wireless power transfer in order to minimize the non-harvested energy caused by the RF energy harvesting sensitivity level, and (iii) channel fading is beneficial for energy harvesting in both PS and TS schemes.