| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain an efficient and reliable evaluation method of a reproduction signal and an optical disk drive using this method by solving such a problem that a circuit scale is index-likely increased in accordance with the increase of a constraint length of PRML system when Euclidean distance is calculated by determining coincidence of a binarization bit column and a predetermined evaluation bit column for evaluating quality of the reproduction signal in a large capacity optical disk system having the constraint length of 5 or larger. <P>SOLUTION: The continuous number of 2T to be contained in the predetermined evaluation bit column is expressed as i, and the evaluation bit column is considered with respect to a bit column of length (5+2i), and a determination process is executed whether the predetermined evaluation bit column is contained in the binarization bit column. Error vectors to be obtained from a target signal corresponding to the evaluation bit column and a target signal formed from the binarization bit column are prepared to select one by a result of the determination process. Simultaneously, an equalization error vector, which is obtained from the target signal to be formed from the binarization bit column and the reproduction signal, is calculated and by computing an inner product of the equalization error vector and the selected error vector, the circuit scale required for evaluation of the reproduction signal can be reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
