| 摘要 |
<p>PURPOSE: To provide a transmitter for embedding a digital signal into an analog television signal and a receiver for recovering the digital signal embedded in the analog television signal. CONSTITUTION: This device is composed of a composite video signal source 7, an information source 13 of digital information, an error-correcting coder 14 for inserting a forward error correction code into the digital information and converting it into a 1st bit serial signal, a frequency modulation transmitter 4 for modulating and outputting the frequency of audio carrier corresponding to an audio signal, a 1st residual side wave band amplitude modulation transmitter 8 for modulating the amplitude of a video carrier corresponding to a composite video signal and generating an output signal, a 2nd residual side wave band amplitude modulation transmitter 12 for modulating and outputting the amplitude of a suppressed carrier corresponding to a binary phase shift keying signal, and a frequency multiplexer 5 for combining the respective output signals of 1st and 2nd residual side wave band amplitude modulation transmitters 8 and 12 with the output signal of frequency modulation transmitter 4, so that the suppressed carrier can be phased orthogonally with the video carrier.</p> |
