Reduced-complexity UWB time-reversal techniques and experimental results

Abstract

This paper presents a reduced-complexity time reversal technique for ultra-wideband (UWB) communications. Time reversal takes advantage of rich scattering environments to achieve signal focusing via transmitter-side processing, which enables the use of simple receivers. The goal of this paper is to demonstrate a UWB time reversal system architecture based on experimental results and practical pulse waveform, taking into account some practical constraints, and to show feasibility of UWB time reversal. Pre-decorrelating in addition to time reversal processing is considered for a downlink multiuser configuration. Multiple transmit antennas are employed to improve the performance.Index Terms-Time reversal, ultra-wideband (UWB), autocorrelation correlation demodulation (ACD), and multiple antennas.

Time-Reversal Wireless Paradigm for Green Internet of Things: An Overview

“…Experimental validations of TR technique with EM waves have been conducted in [24], [39]- [45], including the demonstration of spatial and temporal focusing properties [24], [39]- [45] and channel reciprocity [24], [41]. The feasibility of applying TR technique into ultra-wideband (UWB) communications has been studied in [46]- [48] with the focus on the bit error rate (BER) performance through simulation. A system-level theoretical investigation and comprehensive performance analysis of a TR-based multiuser communication system was conducted in [25], where the concept of TRDMA was proposed.…”

Cognitive radar for the localization of RFID transponders in dense multipath environments

“…[16]) but it has also been discussed for UWB (e.g. [5], [6]). Some intuitive arguments can be given, why TR processing can be a good choice for this CR, while a proof of optimality is out of scope of this paper.…”

“…By this dependence, the transmitter controls the accuracy of the state estimation in the RX, an essential property of a CR [1]. 6 …”

“…The measurement log-likelihood function is 5 Note that a path-loss model is not included in this example. 6 It is noted that the noise component w(t; θ TX (p ℓ ),x ℓ ) also represents the cross-terms k = k ′ from the intermediate convolution result. approximated as the inner product of the received signal and a hypothesized channel response (cf.…”

“…Adaptive illumination of the environment can exploit known deterministic multipath components (MPCs) through a TX-side environment model that is learned at runtime. Time reversal (TR) processing [5], [6] is proposed, which is expected to be beneficial to overcome the degenerate pinhole channel of a backscatter radio system [7]. At the receiver side, deterministic MPCs can aid the target localization problem and overcome non-line-of-sight (NLOS) situations [8].…”