Method and device for supplementary data transmission in TV channels

摘要

The method derives a system clock signal (ST) and a video pulse (BI) from the line sync pulses (ZI) by counting-out and evaluating areas free from information. Video and audio signals are digitised, stored, buffered, compressed and multiplexed into the data clock signal. Called-up additional data are superimposed, pref. after being band-limited, on the colour composite video signal (FBAS). At the receiver, the data are regenerated by clamping, limiting and digitisation followed by digital correlation and decision. The additional data are demultiplexed and separated into video and audio for decompression and reproduction in analogue form.