Patent ID: 7203232

Claim:
An apparatus for adjusting a filter tap length for an adaptive equalizer comprising: a multipath detector for detecting multipath information from a difference between the correlation values of input data applied to the adaptive equalizer and a training sequence, and an auto correlation value of a training sequence when the training sequence is valid; and a tap length adjusting unit for generating a tap length control signal based on positions of the pre-/post-ghosts farthest from a main tap by using the detected multipath information and a field sync signal, wherein the tap length adjusting unit comprises: a threshold comparator for comparing the detected multipath information with a threshold value and outputting only correlation values exceeding the threshold value; a counter for counting field sync sections delayed by an amount of time taken in obtaining the correlation values; a ghost detector for detecting a position of a ghost from the correlation values obtained by the threshold comparator for the delayed field sync sections counted by the counter; and a tap length table for matching the tap length so as to cover the detected pre-/post-ghosts to output the tap length control signal.