Abstract: A system for a direct digital down conversion of a 10.8 MHz intermediate frequency signal in the personal handy phone system. The present invention includes a system that enables a direct digital down conversion of a 10.8 MHz intermediate frequency signal into a digital baseband signal within cell stations and portable stations of the personal handy phone system. To perform this direct digital down conversion of a 10.8 MHz intermediate frequency signal, one embodiment of the present invention uses a hard limiter circuit, a sampler circuit and a digital down converter circuit. The hard limiter circuit of the present invention receives a 10.8 MHz intermediate frequency signal, utilized within cell stations and portable station of the personal handy phone system, and provides a threshold for it. The sampler circuit uses a 19.2 MHz oscillating clock signal to sample the intermediate frequency signal that is output from the hard limiter circuit. Due to spectral leakage, the 10.

Abstract: A cellular communications device for communicating over a cellular network control channel of a cellular mobile radiotelephone (CMR) system. A transmitter can transmit a data message formatted to correspond to an identification signal transmitted by a cellular radiotelephone when that device identifies itself to the CMR system. The data message contains selected data and is transmitted via the reverse overhead control channel of the cellular network control channel. A receiver can receive command signals from a mobile switching center of the CMR system via a forward overhead control channel (FOCC) of the cellular network control channel. A controller controls operation conducted by the transmitter and the receiver.