METHOD AND SYSTEM TO LOCATE A MOBILE SUBSCRIBER IN A CDMA COMMUNICATIONS SYSTEM.

摘要

A method for geographically placing a subscriber unit (401) using a plurality of base stations (36) in a wireless CDMA communication system, each base station (36) transmitting a first spread spectrum signal with a first code, transmitting the subscriber unit (401) to the base station (36) of the first received signal, for each first received signal, a second spread spectrum signal, with a second code, synchronized with said first received signal, the method being characterized by : for each first signal received by the subscriber unit (401), analyze a pulse response of multi-path components of the first signal received in order to determine a first component received; at each base station (36), analyze a pulse response of multipath components of the second signal received by that base station in order to determine a first received component; at each base station (36), determine the distance between that base station (36) and the subscriber unit (401) based, in part, on a timing difference between the second code of the second received signal and the first code of the first signal transmitted by that base station and the first received component determined from the second signal received by that base station; and determine the location of the subscriber unit (401) based, in part, on the determined distances, the fixed situation of each base station (36) and an estimate of maximum probability.