POSITION ENHANCED COMMUNICATION SYSTEM

摘要

A cellular telephone system (figure 1) having three or more cell sites with each cell site having a source of cellular communication signals (7-10) and an RF transmitter (7-12) and antenna (7-13) for broadcasting the cellular communication signals. A direct sequence spread spectrum waveform carrying navigation signals is embedded in the cellular communication signals, including controlling the signal strength of the navigation signals so that the combined energy of the navigation signals from all cell sites at any location is at least a predetermined energy level below the energy level of the cellular communication signals. Each cell site includes timing for timing the operation of a GPS receiver.