Being the signal quality evaluation manner which evaluates the quality of the above-mentioned regenerative signal from pass metric difference of the pass 2 PRML (Partial Response Maximum Likelihood) decode signal quality evaluation

摘要

PROBLEM TO BE SOLVED: To provide a signal quality evaluation device which can evaluates the quality of a reproduced signal with simple circuit constitution.;SOLUTION: The device has a pathmetric difference detection part 102 which performs PRML (partial response maximum likelihood) decoding of a reproduced signal of an optical disk 100 reproduced by a signal reproduction part 101 and detects the pathmetric difference between two paths inputted to respective states of a trellis diagram in the PRML decoding process, a peak frequency detection part 103 which detects the frequency of the detected pathmetric difference and detects the peak frequency from a distribution of the frequencies, and a reproduced signal quality evaluation part 104 which evaluates the quality of the reproduced signal according to the detected peak frequency.;COPYRIGHT: (C)2003,JPO