INFORMATION RECORDING MEDIUM EVALUATION METHOD, INFORMATION RECORDING MEDIUM, INFORMATION RECORDING MEDIUM MANUFACTURING METHOD, SIGNAL PROCESSING METHOD, AND ACCESS CONTROL DEVICE

摘要

An information recording medium evaluation method includes: a step of receiving a digital reproduction signal generated from an analog reproduction signal indicating the information reproduced from an information recording medium and shaping the waveform of the digital reproduction signal; a step of subjecting the shaped digital reproduction signal to most likelihood decoding and generating a digitized signal indicating the result of the most likelihood decoding; and a step of calculating the quality of the digital reproduction signal according to the shaped digital reproduction signal and the digitized signal. When calculating a reproduction signal quality by using the PRML method containing a plurality of zero cross portions in a confluent path of minimum different metric, it is possible to use only a state transition pattern containing only one zero cross portion in the confluent path of the non-minimum difference metric.