DETERMINATION OF LOCATION USING TIME-SYNCHRONIZED CELL SITE TRANSMISSIONS

摘要

The location of a subscriber device (22) in a wireless cellular communications system is established by transmitting digital data signals to a cellular digital data receiver of the subscriber device (22) from at least three different cellular cell site transmitters (26) at known locations. Each data signal has a time-synchronized synchronization signal, preferably synchronized through the time signals of the global positioning system. The time of arrival of each of the time-synchronized synchronization signals is determined with respect to an internal clock of the receiver. The location of the subscriber device (22) is established from the locations of the cell sites (24) and the times of arrival of the synchronization signals relative to the internal clock.