Patent ID: 7801559

Claim:
A method for transmitting and receiving digitally modulated wireless signals using an analog FM transceiver, the analog FM transceiver having a transmit speech audio frequency band, a receive speech audio frequency band substantially equal to the transmit speech audio frequency band, a subaudible frequency band, a direct microphone audio input, and a direct speaker audio output, said method comprising: generating, in a baseband digital spectrum translator external to the analog FM transceiver, a baseband transmit signal occupying frequencies substantially within the transmit speech audio frequency band of the analog FM transceiver; applying the generated baseband transmit signal to the direct microphone audio input to thereby transmit a digitally encoded RF TX signal having a constant envelope; using the analog FM transceiver to receive a digitally encoded RF RX signal with a constant envelope and to generate a baseband receive signal using the digitally encoded RF RX signal; and generating, in the baseband digital spectrum translator, a speaker audio signal using the baseband receive signal.