摘要 |
In a recording/reproducing system that performs PRML decoding, a suitable evaluation value for setting a recording condition can be obtained with a simple structure. It is assumed that a value corresponding to a difference between a difference metric between a maximum likelihood path for an equalized signal that is fed to maximum likelihood decoding processing and a path in a bit-advanced shift direction and a difference metric between the maximum likelihood path for the equalized signal and a path in a bit-delayed shift direction is a signal quality evaluation value dSAM. Further, the signal quality evaluation value dSAM is calculated using an equalization error value ek which is an error between an equalized signal value fed to the maximum likelihood decoding processing and an ideal equalized signal value determined from a decoded signal obtained as a result of the maximum likelihood decoding processing. |