| 摘要 |
PURPOSE:To restore a signal correctly to an original composite video signal without causing any group delay distortion by constituting a digital filter of a transversal filter. CONSTITUTION:All filters in a video signal transmission equipment are constituted of linear-phase filters. In a transversal filter shown in the figure, coefficient devices 35, 37 multiply the same coefficient to an input signal. Similarly, coefficient devices 34, 38 and coefficient devices 33, 39 multiply respectively the same coefficient to the input signal. In constituting the coefficient devices symmetrically about the left/right, the linear-phase filter is obtained. Thus, in using the filter of the linear-phase in this way, a video signal high-frequency component is added to a low-frequency component while the phases are matched accurately, and the signal is restored accurately to the original composite video signal.
|
