Process or Device for transmitting a HDTV signal and a standard television signal to two standard television channels and for decoding the corresponding HDTV signal

摘要

There is disclosed a device and a circuit to provide compatibility between NTSC television and HDTV by using dual channel transmission system. One embodiment may be arranged with means for generating a first display signal, a pre-filter (13) which prevents aliasing by filtering the first display signal, a first scanning converter (14), a first NTSC encoder (15), a first RF modulator (16), a delay unit (17), a first line rejecter (18), a second scanning converter (19), a first postfilter (20), a second line rejecter (21), a subtractor, a first frequency shifter (23), a signal reconstruction circuit (24), a second NTSC encoder (25), and a second RF modulator (26).