Joint sequential target state estimation and clock synchronization in wireless sensor networks

Clock synchronization is crucial to a wireless sensor network but often difficult to maintain. In this paper, we propose a joint estimation method to estimate both target states and clock synchronization status based on sensor observations from an unsynchronized wireless sensor network. We build a multi-sensor state-space model to connect clock synchronization status with sequential state transition. We use the expectation-maximization algorithm, together with Monte Carlo approximations, for joint estimation. Numerical examples show that the proposed method converges to the true synchronization status and improves the accuracy of sequential state estimation by considering the synchronization status.