INFORMATION RECORDING AND REPRODUCING DEVICE AND ITS SIGNAL EVALUATING METHOD

摘要

PROBLEM TO BE SOLVED: To compute the evaluation value of signal quality to a reproduced signal with small computational complexity by preliminarily preparing a table of various patterns to patterns easy to be mistaken. SOLUTION: An information recording and reproducing device which obtains a recognition signal using a partial response maximum likelihood (PRML) recognition system is equipped with; correct patterns and their ideal signals; incorrect patterns corresponding to the correct patterns and their ideal signals; a table 204 of Euclidean distances among correct patterns and incorrect patterns; a means 202 which computes differences of Euclidean distances among ideal signals of the correct patterns and the reproduced signal and Euclidean distances among ideal signals of the incorrect patterns and the reproduced signal when the recognition signal is in agreement with one of patterns of the table; and the means 202 which evaluates the recognition signal using an average and an standard deviation of the distribution of the differences. Thus, the information recording and reproducing device can compute highly precise evaluation value of the reproduced signal with the small computational complexity. COPYRIGHT: (C)2005,JPO&NCIPI