Improved PAL by a Combination of NTSC-SECAM-PAL

In the existing TV standards NTSC, SECAM and PAL the luminance and chrominance components are transmitted in a frequency multiplex format with a full compatibility to monochrome characteristics. As the spectrum of the modulated subcarrier is shared with the high frequency components of the luminance signal, cross effects normally arise after demodulation which impair the picture quality. Moreover the bandwidth of the luminance signal is restricted by notch filters in the coder and in the decoder.