Patent ID: 7428203
Filing Date: 2008-09-23
Classification: G11B

Abstract:
1. A signal evaluation method configured to evaluate a reproduction equalization signal reproduced from a recording medium by use of a PRML (partial response and maximum likelihood) discrimination method, said method comprising the steps of: detecting matching between discrimination data and a plurality of predetermined bit pattern pairs of different groups; calculating a bit pattern and corresponding two ideal responses when the matching is detected; obtaining Euclidean distances between the two ideal responses and equalization reproduced signals; obtaining a difference between the Euclidean distances; obtaining a mean value and a standard deviation with respect to the difference between the Euclidean distances; calculating a miss-discrimination probability F(0) of the predetermined bit pattern from the mean value and the standard deviation; and calculating a quality evaluation value of a reproduction signal based on the miss-discrimination probability F(0), an appearance probability of the predetermined bit pattern, and a Hamming distance between the predetermined bit pattern pairs.