METHOD FOR THE HIGH ACCURACY GEOLOCATION OF OUTDOOR MOBILE EMITTERS OF CDMA CELLULAR SYSTEMS

摘要

A high-accuracy method for the geolocation, without the collaboration of th e network, of outdoor mobile emitters of a CDMA cellular system, based on the ability to distinguishing between line-of sight and reflected signals. The method employs time-of flight and angle-of arrival information in order to determine whethe r a signal received by each of two or more interceptors situated at different locations is line-of-sight or reflected. Time-of flight information is obtained with the aid of the reverse link of a mobile of interest. At those instances in time when the signal received at two or more interceptors is line-of sight, the location of the mobile can be accurately determined using conventional direction-finding techniques. Since the signal received by an interceptor from a mobile may be very weak, adaptive threshold digital signal processing techniques may be employed to control the probability of detectio n and the probability of false alarms.