Time Reversal for Multiple Access and Mobility: Algorithmic Design and Experimental Results

TL;DR

This paper introduces an iterative Time-Reversal Division Multiple Access (TRDMA) method that reduces interference in multi-user wireless communication, validated through experiments in a simulated indoor environment with mobile users.

Contribution

The paper proposes an iterative TRDMA algorithm that enhances multi-user wireless communication by reducing interference, with experimental validation in a rich scattering environment.

Findings

Iterative TRDMA reduces inter-user interference more effectively than conventional methods.

The approach performs well in environments with mobile users.

Experimental results demonstrate improved efficiency with fewer iterations.

Abstract

Time Reversal (TR) has been proposed as a competitive precoding strategy for low-complexity wireless devices relying on Ultra-WideBand (UWB) signal waveforms. However, when TR is applied for multiple access, the signals received by the multiple users suffer from significant levels of inter-symbol and inter-user interference, which requires additional processing for mitigation by each receiving user. In this paper, we present an iterative Time-Reversal Division Multiple Access (TRDMA) approach that aims to dim the latter interference levels. The performance of iterative TRDMA is evaluated experimentally in a reverberation chamber that mimics a rich scattering indoor wireless propagation environment. The improved efficiency, in terms of the number of algorithmic iterations, of the proposed approach compared to conventional TRDMA, is demonstrated. We also consider a mobile user configuration, where the position of the receiver changes between the channel estimation and data transmission steps. It is showcased, even for this experimental setup, that the proposed iterative TRDMA approach is more efficient than conventional precoding schemes.