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用 PAL 制可以消除正交平衡调幅在有相位误差时两个色差信号的相互串色。因为该制式采用了逐行倒相技术,使在时间和频谱上都重迭的 U、V 信号在频谱上错开,同时仍保留着正交调制信号的特性。消除色度信号串扰的过程为,信号编码时,利用半行频的逐行倒相开关对 V 分量逐行倒相,使 V 和 U 色度信号的频谱谱线错开 f_H/2;信号解码时,利用延迟线作为存贮器,将前后两行色度信号在加法和减法器中平均,通过电平均的方法,抵消信号在传输过程中相位失真所带来的 U 和 V 色度信号的相互串扰。在 VHS 录像技术中,采用无保护带的高密度记录方法,以消除相邻磁迹间色度信号的串扰。消除串扰的过程类似 PAL 制电视技术中消除色度信号的串扰过程,在记录状态,对 CH-2磁迹色度信号低副载波
With PAL system can eliminate the quadrature balance amplitude modulation in the phase error of the two color difference signal mutual cross-color. Because this system adopts the progressive inverting technology, the U and V signals overlapped in time and spectrum are spectrally staggered while still maintaining the characteristics of the quadrature modulated signal. The process of eliminating crosstalk of the chrominance signal is that when the signal is encoded, the V component is inversed line by line with a progressive inverter with a half line frequency, so that the spectral lines of the V and U chrominance signals are shifted by f_H / 2; when the signal is decoded , The use of the delay line as a memory, the first two lines of chrominance signals in the adder and subtractor averaging, through the average method to offset the signal phase distortion in the transmission caused by U and V chrominance signal mutual Crosstalk. In VHS recording technology, a high-density recording method without a guard band is employed to eliminate crosstalk of chromatic signals between adjacent tracks. The process of eliminating crosstalk is similar to the crosstalk process of eliminating chrominance signals in the PAL television technology. In the recording state, the CH-2 track chrominance signal is low in subcarriers