Time of Arrival Estimation for Backscatter UWB

Backscatter communication, a passive transmission technique, is widely employed in Internet of Things (IoT). For localization purpose, Ultra-Wideband (UWB) technology offers large bandwidth and high time domain resolution, making it ideal for various positioning applications in IoT. In this letter, we show that the time indices of the backscatter UWB pulses are topologically correlated in multipath propagation environments. Based on this, we propose a novel TOA estimation method which can dramatically improve the estimation accuracy in practical SNR regimes. To our best knowledge, this is the first time that a TOA estimator for backscatter UWB is proposed by taking the advantage of the topological structure of the time indices of the pulses.