COMPATIBLE FREQUENCY-DIVISION MULTIPLEX TELEVISION SYSTEM

摘要

To obtain an improved PAL-compatible television system with reduced crosstalk between luminance and chrominance spectra, which can be adapted to existing terrestrial channels, the luminance signal spectrum is split on the emission side into a low-frequency part Y1 and a high-frequency part Y2 which is modulated onto a carrier. This modulation is effected in such a way that the spectrum of the resultant modulation signal Y*2 lies in a region of the three-dimensional PAL spectrum which is virtually free of useful signal spectra within the given channel width. The modulation signal Y*2 is transmitted with the low-frequency par Y1 of the luminance signal spectrum in the form of data concerning the luminance Y in the PAL-C signal. On the reception side, an improved television receiver filters out the modulation signal Y*2 from the received PAL-C signal and demodulates it. The signal so obtained, which corresponds to the high frequency part Y2 of the luminance signal spectrum, is added to the low-frequency part Y1 of the luminance signal spectrum separated from the received PAL-C signal. A conventional PAL receiver processes only the low-frequency part Y1 of the luminance signal and is not subject to interference by the modulation signal Y*2 transmitted with the latter.