Joint localization and clock synchronization for wireless sensor networks

TL;DR

This paper introduces a unified approach for joint localization and clock synchronization in wireless sensor networks, using a least-squares estimator and CRLB analysis to improve accuracy in asynchronous environments.

Contribution

It presents a novel model and estimator that simultaneously address localization and synchronization, unifying two traditionally separate problems in sensor networks.

Findings

The proposed estimator effectively estimates position and clock parameters.

CRLB provides a benchmark for estimator performance.

Joint approach improves accuracy over separate methods.

Abstract

A fully-asynchronous network with one target sensor and a few anchors (nodes with known locations) is considered. Localization and synchronization are traditionally treated as two separate problems. In this paper, localization and synchronization is studied under a unified framework. We present a new model in which time-stamps obtained either via two-way communication between the nodes or with a broadcast based protocol can be used in a simple estimator based on least-squares (LS) to jointly estimate the position of the target node as well as all the unknown clock-skews and clock-offsets. The Cram\'er-Rao lower bound (CRLB) is derived for the considered problem and is used as a benchmark to analyze the performance of the proposed estimator.