Patent ID: 6459903
Filing Date: 2002-10-01
Classification: G01S,H04W

Abstract:
A method for locating a mobile station (MS) capable of communicating with at least three base stations (BSs) each having at least two antennas, comprising the steps of:(a) calculating the respective distance between said MS and said each BS based on a Time of Arrival (TOA) method using an MS signal arriving at said each base station; (b) determining an overlap area, defining a first estimated MS location area, by an intersection of circles with each radius of said circles corresponding to said calculated distance between said MS and said each BS; (c) estimating the location of said MS based an Angle of Arrival method(AOA), defining a second estimated location area, wherein said AOA method includes the steps of: (c)(i) receiving time of signals received through two antennas of said each BS; (c)(ii) estimating the MS location based on an angle between said each antenna of said each BS with respect to said MS, wherein said angle is calculated from the phase difference between the received signals and a communication frequency of the signals; and (c)(iii) estimating said second location area defined by the lines connecting said each BS to said MS based on said AOA method; and, (d) determining a new location of said MS defined by a common area of said first location area and said second location area.