| 摘要 |
A television ghost cancellation system is provided which includes a delay line having an input coupled to receive video signals which include a training signal component. The delay line provides a delay to the video signals which is substantially equal to the delay of the ghost of the training signal with respect to the training signal when a ghost signal is present. This delay causes a delayed training signal to appear at the output of the delay line at the same time that its ghost is applied to the input of the delay line. The delayed signal at the output of the delay line is applied to a control amplifier, which is coupled in a feedback loop with an amplitude comparator and a sample-and-hold circuit. The amplitude comparator compares the delayed training signal with the ghost at the input of the delay line and produces an error signal indicative of the amplitude differences between the two signals. The error signal is stored by the sample-and-hold circuit and is used to develop a control signal for the control amplifier so that the control amplifier will produce a pseudo-ghost signal which is of equal amplitude and opposite polarity as the training signal ghost during the sampling interval. The pseudo-ghost signal is combined with the original video signal to produce a deghosted output signal.
|
