Variational message passing for joint localization and synchronization in wireless sensor networks

We consider an asynchronous sensor network where target sensors aim to locate themselves unambiguously. Timing information is a vital requirement for time-based localization. Joint localization and synchronization estimation can improve position accuracy and reduce both communication overhead and power cost. In this paper, a novel distributed cooperative joint localization and synchronization algorithm based on factor graph and variational message passing (VMP) is proposed. We linearize the nonlinear terms in observation function in order to obtain a closed Gaussian form solution of the joint estimation problem. Simulation results show that the proposed joint localization and synchronization method performs very close to those sample based approaches with much lower complexity and communication overhead.