| This dissertation considers the problem of determining the locations of multiple moving mobile cellular phones from data at base stations. Various localization techniques have been developed over the past years. Among them Global Positioning System (GPS), Time Difference of Arrival (TDOA), Angle of Arrival (AOA) and RSS (Radio Signal Strength) techniques are used in mobile wireless communication systems for source localization. The environment of urban area causes multi-path fading and jamming for radio frequencies, and these phenomena reduce the accuracy of source localization algorithms. The new algorithms proposed here make use of multi-path and direct arrivals and estimate the source position based on the total intersection information. A set of receivers are used first to determine the Direction of Arrival (DOA) of the mobiles and all other multi-paths using a high resolution algorithm. The initial estimates include line of sight and multi-path arrivals. Reverse ray tracing is then used to determine the possible source locations. Every intersection of two rays represents a possible source location, and in this context the various algorithms are investigated for determining the best source location. In one such case, the sum distance is minimized. The other one is a polygon method where a sequence of polygons are developed and used for source location identification.;These problems have applications in emergency management, medical and military situations where determining locations of mobiles are crucial. |
