JOINT LOCALIZATION AND CLOCK SYNCHRONIZATION FOR WIRELESS SENSOR NETWORKS

A fully-asynchronous network with one target sensor and a few anchors (nodes with known locations) is considered. Lo-calization and synchronization are traditionally treated as two separate problems. In this paper, localization and synchro-nization 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 tar-get node as well as all the unknown clock-skews and clock-offsets. The Cramér-Rao lower bound (CRLB) is derived for the considered problem and is used as a benchmark to analyze the performance of the proposed estimator. Index Terms — Clock synchronization, clock-skew, clock-offset, localization, wireless sensor networks