SIGNAL EVALUATION METHOD AND SIGNAL EVALUATION DEVICE

摘要

Provided is a signal evaluation method which evaluates a reproduction signal according to a digitization signal generated from a reproduction signal reproduced from an information recording medium by using the PRML method. The signal evaluation method includes: a step for detecting a pattern of paths corresponding to the digitization signal and combined into the same state; a step for acquiring an ideal value of a correct pattern corresponding to the digitization signal and an ideal value of an error pattern corresponding to the correct pattern; a step for calculating a difference between the distance of the ideal value of the correct pattern and the reproduction signal and a difference between the distance of the ideal value of the error pattern and the reproduction signal; a step for calculating a predicted error rate for each of predetermined pattern groups in the PRML method according to the differences; and a step for calculating a standard deviation corresponding to the entire error rate added by the error rate of each predetermined pattern group to be used for evaluating the reproduction signal.