# Wireless Information and Power Transfer over an AWGN channel: Nonlinearity and Asymmetric Gaussian Signaling

## TL;DR

This paper investigates simultaneous wireless information and power transfer over an AWGN channel using a validated nonlinear energy harvester model, revealing a tradeoff between power delivery and information rate influenced by asymmetric Gaussian signaling.

## Contribution

It introduces an experimentally-validated nonlinear model for energy harvesting and derives a new inner bound for the rate-power region considering asymmetric Gaussian inputs.

## Key findings

- Nonlinear harvester model significantly affects the R-P tradeoff.
- Asymmetric Gaussian signaling optimizes the power-information balance.
- Inner bound demonstrates the impact of input distribution on system performance.

## Abstract

Simultaneous transmission of information and power over a point-to-point flat-fading complex Additive White Gaussian Noise (AWGN) channel is studied. In contrast with the literature that relies on an inaccurate linear model of the energy harvester, an experimentally-validated nonlinear model is considered. A general form of the delivered Direct Current (DC) power in terms of system baseband parameters is derived, which demonstrates the dependency of the delivered DC power on higher order statistics of the channel input distribution. The optimization problem of maximizing Rate-Power (R-P) region is studied. Assuming that the Channel gain is available at both the receiver and the transmitter, and constraining to independent and identically distributed (i.i.d.) channel inputs determined only by their first and second moment statistics, an inner bound for the general problem is obtained. Notably, as a consequence of the harvester nonlinearity, the studied inner bound exhibits a tradeoff between the delivered power and the rate of received information. It is shown that the tradeoff-characterizing input distribution is with mean zero and with asymmetric power allocations to the real and imaginary dimensions.