Track initiation for blind mobile terminal position tracking using multipath propagation

Blind localization and tracking of mobile terminals in urban scenarios is an important requirement for offering new location based services, handling emergency cases of non-subscribed users, public safety etc. In this context, we propose a track-before-detect scheme, taking explicit advantage of multipath propagation in an urban terrain by using a priori information about the known locations of the main scattering objects such as buildings. A ray-tracing technique allows the prediction of the directional and temporal structure of the received multipath components for an arbitrary transmitter position. We consider a single observing station where the direction and the relative time of arrival of the received multipath components can be estimated by an antenna array. By a likelihood function, which is algorithmically defined for a randomly distributed set of potential transmitter positions, these measurements are compared with those being expected by ray tracing. This likelihood function is the key component of a track-before-detect scheme providing initial state estimates for mobile transmitter tracking using a particle filtering technique.