Patent ID: 6477125
Filing Date: 2002-11-05
Classification: G11B,H03M

Abstract:
A decoding apparatus for decoding a signal reproduced from an optical disc comprising:automatic gain control means for controlling an envelope level of a waveform of said signal to a predetermined level; waveform equalizing means having a frequency characteristic for waveform-equalizing said signal from said automatic gain control means to remove reproduction waveform distortion of said signal, said frequency characteristic being changed in accordance with at least a tap coefficient; binary coding means for binary-coding an output of the waveform equalizing means; a phase-locked-loop circuit for generating a bit synchronizing clock signal on the basis of an output of said binary coding means; a/d converting means for a/d-converting an output of said waveform equalizing means in response to said bit synchronizing clock signal; Viterbi decoding means including metric operation means for Viterbi-decoding said output of the a/d converting means in response to said bit synchronizing clock signal to output a bit stream, said metric operation means generating a metric operation result from an output of the a/d-converting means and prediction data, said Viterbi decoding means Viterbi-decoding said output of said a/d converting means with said metric operation result; error operating means for outputting an equalizing error from the output of said a/d converting means and waveform equalizing target data; coefficient generation means for generating said tap coefficient from said equalizing error to minimize the equalizing error; and data predicting means for generating said prediction data in accordance with said output of said a/d converting means.