Robust Ambient Backscatter Communications with Polarization Reconfigurable Tags

TL;DR

This paper introduces a polarization reconfigurable antenna for ambient backscatter tags, significantly improving robustness against interference and enhancing communication reliability in IoT applications.

Contribution

It proposes a novel polarization reconfigurable tag design that adapts radiation patterns to mitigate interference, a first in ambient backscatter communication systems.

Findings

Reconfigurable tags outperform nonreconfigurable ones in interference environments.

Simulation and experiments show near-ideal performance with limited polarization directions.

Improved robustness in line-of-sight and scattering environments.

Abstract

Ambient backscatter communication system is an emerging and promising low-energy technology for Internet of Things. In such system, a device named tag, sends a binary message to a reader by backscattering a radio frequency signal generated by an ambient source. Such tag can operate without battery and without generating additional wave. However, the tag-to-reader link suffers from the source-to-reader direct interference. In this paper, for the first time, we propose to exploit a "polarization reconfigurable" antenna to improve robustness of the tag-to-reader link against the source-to-reader direct interference. Our proposed new tag sends its message by backscattering as an usual tag. However, it repeats its message several times, with a different radiation pattern and polarization, each time. We expect one polarization pattern to be better detected by the reader. We show by simulations and experiments, in line-of-sight and in richly scattering environment, that a polarization reconfigurable tag limited to 4 polarization directions outperforms a nonreconfigurable tag and nearly equals an ideally reconfigurable tag in performance.