Asymmetric Modulation Design for Wireless Information and Power Transfer with Nonlinear Energy Harvesting

TL;DR

This paper introduces an asymmetric PSK modulation scheme for SWIPT that leverages nonlinear energy harvesting models to significantly enhance the rate-energy tradeoff in wireless power and information transfer systems.

Contribution

It proposes a novel asymmetric PSK modulation design that improves SWIPT performance by considering nonlinear energy harvesting effects, a relatively unexplored area.

Findings

Asymmetric PSK outperforms symmetric PSK in SWIPT rate-energy tradeoff.

Nonlinear rectifier modeling is crucial for accurate energy harvesting evaluation.

The proposed scheme enhances the efficiency of wireless power and information transfer.

Abstract

Far-field wireless power transfer (WPT) and simultaneous wireless information and power transfer (SWIPT) have become increasingly important in radio frequency (RF) and communication communities recently. The problem of modulation design for SWIPT has however been scarcely addressed. In this paper, a modulation scheme based on asymmetric phase-shift keying (PSK) is considered, which improves the SWIPT rate-energy tradeoff region significantly. The nonlinear rectifier model, which accurately models the energy harvester, is adopted for evaluating the output direct current (DC) power at the receiver. The harvested DC power is maximized under an average power constraint at the transmitter and a constraint on the rate of information transmitted via a multi-carrier signal over a flat fading channel. As a consequence of the rectifier nonlinearity, this work highlights that asymmetric PSK modulation provides benefits over conventional symmetric PSK modulation in SWIPT and opens the door to systematic modulation design tailored for SWIPT.