| 摘要 |
<p>A composite signal which comprises a video signal situated in the base band and a frequency-modulated audio signal situated outside the base band is coded by an N-bit pulse code modulator or an N-bit noise-shaped pulse code modulator with inadequate quality for, for example, N < 5 (in particular for N = 1) because, after modulation, demodulation and decoding, the video signal is found to affect the audio signal if, as is usual, the amplitude of the video signal is, for example, ten times greater than the amplitude of the frequency-modulated audio signal. If the amplitude of the video signal is not more than five times greater (in the ideal case one and a half times greater) than the amplitude of the frequency-modulated audio signal, the effect mentioned is apparently considerably reduced. <IMAGE></p> |
