| 摘要 |
PROBLEM TO BE SOLVED: To provide a reproduced signal evaluating method aiming at polarity transition of a reproduced signal, namely polarity change of a recording mark sequence in an index correlative with the error rate of the binarized result obtained by maximum likelihood decoding. SOLUTION: A recording series of a state transition stream having a prescribed Euclidean distance in the maximum likelihood decoding is detected corresponding to the polarity change of recording codes of the recording series, a likelihood difference of the state transition stream between the most certain state transition stream from a branch of the state transition stream to a junction of the state transition stream in the recording series and the second certain state transition stream is obtained and statistical processing of the likelihood difference is individually performed corresponding to polarity change of the recording series to evaluate the quality of the reproduced signal. COPYRIGHT: (C)2006,JPO&NCIPI
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