Patent attributes
A pattern of an input sync signal is compared with sub patterns in a first sync pattern. The sub patterns in the first sync pattern are equal to the patterns of true sync signals, respectively. When the pattern of the input sync signal agrees with none of the sub patterns in the first sync pattern, the pattern of the input sync signal is compared with sub patterns in a second sync pattern. The sub patterns in the second sync pattern have temporal fluctuations with respect to the patterns of the true sync signals. Each of the sub patterns in the second sync pattern is assigned to only one of the true sync signals. It is determined that a sync signal is detected when the pattern of the input sync signal agrees with one of the sub patterns in the first and second sync patterns.
