Factor Graph Approach for Joint Passive Localization and Receiver Synchronization in Wireless Sensor Networks

Obtaining the location of a "passive" target in wireless sensor networks has attracted numerous interest in recent years. This paper considers the passive localization based on time-of-arrival measurements in an asynchronous sensor network where the receivers are with both clock skew and offset. Based on the factor graph model, the beliefs (approximated marginal) of target location and clock parameters can be obtained by executing iterative message passing algorithms. To reduce the huge complexity of particle based method, we propose two approximate approaches to determine parametric Gaussian message passing. Simulation results show that the proposed low complexity algorithm performs close to the particle-based method and attain the Cramer-Rao bound.