| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a transmitting/receiving method and apparatus which is inexpensive and hardly tapped, by using an analog FM dedicated transceiver without having circuitry or software for transmitting/receiving digital data. <P>SOLUTION: A self-contained apparatus 10 converts an audio signal from a microphone 16 into a baseband transmit signal suitable for transmitting with an analog FM transmitter. The self-contained apparatus can also decode baseband receive signals from a direct speaker audio output 31 of an analog FM receiver. The apparatus further includes an analog-to-digital converter 102 for digitizing a received analog signal from the microphone 16 and a pre-modulation processor 108 for processing the digitized signal, wherein a sideband spectrum of the digitized signal is shifted away from subaudible frequencies by a predetermined amount to generate the baseband signal. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
