By Stanley R. Moote, Leitch Video Limited
As television cable systems grow more complex, new problems arise and some become more prominent. One significant problem is co-channel interference. By aligning the synchronizing intervals of all channels, the subjective impairment due to crosstalk can be reduced. This can be accomplished by baseband processing with digital frame synchronizers. A digital frame synchronizer stores the incoming baseband signal and outputs it with the synchronizing interval aligned to that of a reference baseband signal. This storage and retrieval process takes place in the digital domain.
There are other benefits realized with the use of frame synchronizers. Title keying and channel switching techniques are simplified and improved. Since the synchronizing interval is replaced, improvements in post production editing and mixing are achieved. In addition, corrections can be made to the contrast, color and black level.