An NTSC compatible wide screen television system with evolutionary extendibility

A review is presented of the role of the inverse Nyquist filter in quadrature amplitude modulation (QAM) technology and an outline of studio and network issues of this system is given. For two of the problems concerned, i.e., (a) crosstalk caused by ghosting and (b) interference from conventional TV receivers, the authors propose a two-dimensional waveform equalizer, with processing in the time and frequency domain at a transmitter. The encoding and decoding for this wide-screen television system, and the evolutionary extendibility of QAM technology toward further improvement of image and sound quality in a compatible fashion are also discussed.