Technique for generating semi-compatible high definition television signals for transmission over two cable TV channels

摘要

The present invention relates to a technique for generating a Semi-Compatible High Definition Television (SC-HDTV) signal which can be sent over two present-day Cable Television (CATV) channels. In accordance with the present invention, a HDTV signal is formed comprising a line scan rate which is a multiple of the line scan rate of a current conventional TV signal. The SC-HDTV signal is formed therefrom by transmitting a first HDTV line as is and a second HDTV line as a field differential signal transmitted via QAM on the IF or RF carrier of the first line signal at a line scan rate of a current conventional TV signal. Arrangements are also disclosed frDconverting the SC-HDTV signal back into eigher a HDTV or conventional TV signal.