Device and method for detecting sync signal from digital tv signal

Abstract

Method and device for detecting a synchronizing signal from a digital T.V. signal is disclosed. An initial value is stored as a maximum value in each of memories arranged to match to symbols consisting a datastream of the digital T.V. signal. A comparator has a symbol pattern stored therein in advance, which is identical to a symbol pattern of an actual synchronizing signal contained in the digital T.V. signal. Upon reception of the datastreams of the digital T.V. signal, the comparator compares the symbol pattern stored therein already to the symbols in the received datastream in sequence, to provide zero signals if identical and minus values if not identical. An adder adds a signal from the comparator and an initial value stored in a corresponding memory among the memories and stores in the corresponding memory, to update the initial value in each memory. A synchronizing signal detector compares each of the updated initial values to a reference value, for providing the updated initial value as the synchronizing signal when the updated initial value is equal or greater than the reference value. The reference value is set on the basis of the initial value, and can prevent erroneous detection of the synchronizing signal because the reference signal is always higher than any noise signal, such as ghost.