Sequential Doppler Shift based Optimal Localization and Synchronization with TOA

TL;DR

This paper introduces LAS-SDT, an optimal localization and synchronization method that leverages sequential Doppler shift and TOA measurements in TDBS systems, significantly improving accuracy over traditional TOA-only methods.

Contribution

It develops a new LAS method utilizing Doppler shifts in addition to TOA, with variants for velocity and clock drift aiding, and derives the CRLB for these cases.

Findings

LAS-SDT outperforms conventional TOA-only methods in accuracy.

Analytical CRLB shows significant improvements in position, velocity, and clock estimates.

Numerical results confirm the optimal performance of LAS-SDT.

Abstract

Doppler shift is an important measurement for localization and synchronization (LAS), and is available in various practical systems. Existing studies on LAS techniques in a time division broadcast LAS system (TDBS) only use sequential time-of-arrival (TOA) measurements from the broadcast signals. In this paper, we develop a new optimal LAS method in the TDBS, namely LAS-SDT, by taking advantage of the sequential Doppler shift and TOA measurements. It achieves higher accuracy compared with the conventional TOA-only method for user devices (UDs) with motion and clock drift. Another two variant methods, LAS-SDT-v for the case with UD velocity aiding, and LAS-SDT-k for the case with UD clock drift aiding, are developed. We derive the Cramer-Rao lower bound (CRLB) for these different cases. We show analytically that the accuracies of the estimated UD position, clock offset, velocity and clock drift are all significantly higher than those of the conventional LAS method using TOAs only. Numerical results corroborate the theoretical analysis and show the optimal estimation performance of the LAS-SDT.