Radio location of mobile station - comparing received subscriber number with number of mobile to be located, and if coincidence occurs, activating direction finder to determine mobile azimuth, TA value and hence distance and location

摘要

The method involves setting up a radio link between the mobile (MS1) and the base station (BST) responsible for the area in which it is located. Each mobile has an associated subscriber number which is sent uncoded for each connection to enable the base station to detect the mobile with its subscriber number within its geographic cell. A direction finder system (DFS) in the region of the base station has a receiver (MS-DFS), a coupled controller (DFS-ST) and a direction finder (PE). The receiver picks up the downlink between the base station and mobile. The subscriber number is determined in the receiver and/or controller and compared in the controller with the number of a mobile to be located. If coincidence occurs the direction finder is activated to determine the azimuth angle, TA value and hence distance and location of the mobile.