Semi-Blind Multi-Tag Ambient Backscatter Communications Using Radar Signals

TL;DR

This paper introduces a semi-blind iterative decoding approach for multi-tag ambient backscatter communication systems that utilize radar signals as ambient carriers, improving scalability and robustness.

Contribution

It proposes a novel encoding and decoding strategy for multi-tag backscatter systems using radar signals, with scalable algorithms for joint estimation of data and channels.

Findings

Algorithms effectively handle missing measurements

Scalable to multiple tags and payloads

Tradeoffs between transmission rate and error rate

Abstract

In this work, we consider a backscatter communication system wherein multiple asynchronous sources (tags) exploit the reverberation generated by a nearby radar transmitter as an ambient carrier to deliver a message to a common destination (reader) through a number of available subchannels. We propose a new encoding strategy wherein each tag transmits both pilot and data symbols on each subchannel and repeats some of the data symbols on multiple subchannels. We then exploit this signal structure to derive two semi-blind iterative algorithms for joint estimation of the data symbols and the subchannel responses that are also able to handle some missing measurements. The proposed encoding/decoding strategies are scalable with the number of tags and their payload and can achieve different tradeoffs in terms of transmission and error rates. Some numerical examples are provided to illustrate the merits of the proposed solutions.