Source localization in wireless sensor networks with randomly distributed elements under multipath propagation conditions

Abstract

This thesis proposes a least-squares error estimator for line-of-sight, direction of arrival-based localization and a hybrid source localization scheme that addresses multipath propagation for non-cooperative sources using random arrays of wireless sensors. Taking advantage of the dominant reflections, the proposed solution finds the location of a signal source by triangulation using the direction of arrival estimations of both the line-of-sight and the reflected components. It uses a space division multiple access, spread spectrum-based receiver to generate the direction of arrival estimates. The time difference of arrival information is used to discriminate between the line-of-sight and the non-line-of-sight signals and to associate the incoming multipath signal with the corresponding source and reflector pair. In special cases, the proposed scheme is capable of solving the association problem spatially without the need for time difference of arrival information. Simulation results are included to demonstrate that the proposed scheme provides improved estimates by exploiting the non-line-of-sight information.