| 摘要 |
PURPOSE: A device of detecting field synchronization in digital television of vestigial sideband is provided to resolve the problem that a signal applied to a comb filter and a bit resolution having an absolute value become greater due to failure to hard limiting of the input data, and that the complexity of hardware increases due to dual use of even field and odd field. CONSTITUTION: A device of detecting field synchronization in digital television of vestigial sideband comprises a hard limit (21) for hard limiting by determining negative or positive of the inputted data, a comb filter (22) for performing an interference elimination filtering in the output data of the hard limit (21), a data mapping section (25) for mapping the data passed through the comb filter (22) in {-1, 0, 1}, a signal combination section (26) for obtaining a difference between the signal passed through the data mapping section (25) and the reference signal, an absolute value computing section (27) for gaining an absolute value of the output value of the signal combination section (26), an accumulation section (28) for accumulating the output of the absolute value computing section (27) at segment intervals, a synchronization delay section (29) for delaying the output value of the accumulation section (28) by one field, a comparison section (30) for comparing an ultimately accumulated value at one field interval to detect a segment synchronization interval, a minimum value determination section (31) for determining a field synchronization interval with the ultimately accumulated value of the accumulation section (28) according to the comparison result of the comparison section (30), and a confidence coefficient section (32) for outputting the field synchronization interval of the minimum value determination section (31) into a field synchronization signal.
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