Patent ID: 8331953
Filing Date: 2012-12-11
Classification: G01S,H04W

Abstract:
1. A method for estimating the location of a first mobile station from a plurality of mobile stations that receive signals from a plurality of base stations, comprising: (a) determining observed time difference of arrival (“OTDOA”) values at said first mobile station and at a second mobile station between a first signal received from a first base station and a second signal received from a second base station; (b) determining a round trip time (“RTT”) values between said first and second mobile stations and said first base station; (c) selecting an initial locations for said first and second mobile stations that are within a first and second predetermined areas, respectively; (d) determining an estimated base station time offset (“BSTO”) using the selected initial locations, the OTDOA and RTT values, and an iterative search algorithm wherein the iterative search algorithm iterates a predetermined number of steps; (e) determining an estimated location for said first mobile station jointly with the BSTO; (f) storing said estimated location if the estimated location is within a third predetermined area; (g) repeating (a) through (f) within a predetermined time interval; and (h) determining a calculated location for said first mobile station from the stored estimated locations.