Patent ID: 7190979

Claim:
A battery-powered radio, comprising: a receiver circuit, the receiver circuit operable to produce a received signal from a channel; a received signal strength indicator circuit coupled to the receiver circuit, the received signal strength indicator circuit operable to produce an output indicating an amount of power in the channel; a demodulator circuit coupled to the receiver circuit, the demodulator operable to produce a demodulated signal from the received signal; a signal quality indicator coupled to the demodulator circuit; a decoder circuit coupled to the demodulator circuit; and a microprocessor coupled to the receiver, the received signal strength indicator circuit, the signal quality indicator circuit and the decoder circuit; wherein the microprocessor is operable to energize and de-energize the receiver circuit; determine the presence of a carrier with a carrier detect false rate, based, at least in part, on the power of the channel, and to determine an acceptable signal quality with a signal quality false rate, based, at least in part, on an output of the signal quality indicator circuit; wherein the microprocessor is operable to energize the receiver circuit for a first period of time, and, if the carrier is determined to be present, to then maintain the receiver in the energized state until a determination is made as to whether acceptable signal quality has been obtained, and to de-energise the receiver substantially immediately without waiting for expiration of any time period if the carrier is determined to be present and the signal quality is not acceptable.