Patent ID: 6249252
Filing Date: 2001-06-19
Classification: G01S,H04W

Abstract:
A method for providing a location estimate of a wireless mobile station using measurements of wireless signals, comprising:(a) first receiving, when available, a first collection of measurements of wireless signals transmitted between said mobile station and one or more satellites;(b) second receiving a second collection of measurements of wireless signals transmitted between said mobile station and one or more terrestrial communication stations, at least when said first collection is not available, each said communication station including at least one of a receiver for receiving signals from, and a transmitter for transmitting signals to said mobile station;(c) first determining a first location estimate of said mobile station using said first measurements according to an availability of said first collection;(d) second determining a second location estimate of said mobile station using said second measurements according to an availability of said second collection, wherein said second location estimate is obtained from estimating a time of arrival (TOA) of a received signal relative to a time reference at each one of a plurality of wireless signal monitoring stations using an inverse transform whose resolution is greater than Rayleigh resolution;(e) outputting a resulting location estimate obtained using at least one of said first and second location estimates.