Abstract: A wireless communication system has a central computer, one or more wireless access points and one or more personal badges that communicate wirelessly with the one or more wireless access points. The badges provide the user with a communications device that permits the user to initiate telephone calls and conferences, receive telephone calls, receive pages and be located within a particular environment.

Abstract: A signal receiver includes a superregenerative circuit for feeding back a part of an output signal to form part of an input signal through a feedback route to execute a superregeneration, a capacitance element disposed in the feedback route of the superregenerative circuit, a switch for switching the capacitance element, and a PLL circuit for generating a clock signal for switching the switch based on an output of the superregenerative circuit.

Abstract: A controller in a mobile telephone periodically commands GPS circuitry in the mobile telephone to power-on, capture and process GPS satellite signals. The signals are processed to obtain pseudo-range or time-difference data for at least one GPS satellite. After the signals are processed, the pseudo-range or time-difference data, GPS time, and satellite numbers are stored in non-volatile random access memory (RAM) and the GPS circuitry is powered off. When an emergency signal is present, the controller first commands the GPS circuitry to power-on, capture and process signals from four GPS satellites. If signals from at least four satellites are not present, the information stored in non-volatile RAM is read out. The processed data (if available), or else the data read out of the non-volatile RAM, are reported to a central location through the mobile telephone transmitter. The central location can then use the data to compute the present or last valid GPS location of the GPS receiver.