Over-sampled signal equalizer

A method comprising the steps of:

• equalizing an oversampled digital data signal to determine an equalized digital data signal;
• filtering the equalized digital data signal;
• determining a hard decision and reliability of the filtered digital data signal;
• and
• decoding the filtered digital data signal based at least in part on the hard decision and reliability;
• wherein equalizing the oversampled digital data signal comprises:
• receiving a first set of sampled digital data and a corresponding second set of sampled digital data, where samples in the first set of sampled digital data are offset from corresponding one of the samples in the second set of sampled digital data by a phase difference;
• and
• combining one or more samples from the first set of sampled digital data with respective corresponding ones of the samples in the second set of sampled digital data to determine the equalized digital data signal.

A storage device comprising:

• at least one storage medium;
• a read head configured to read data from the storage medium;
• and
• control circuitry coupled to the read head and configured to process data received from the read head;
• the control circuitry comprising:
• read channel circuitry comprising a decoder;
• and
• signal processing circuitry associated with the read channel circuitry, the signal processing circuitry comprising:
• an equalizer having an input coupled to an output of an analog-to-digital converter, the equalizer being configured to determine an equalized digital data signal from an oversampled digital data signal;
• a filter having an input coupled to an output of the equalizer, the filter being configured to filter the equalized digital data signal;
• a detector having an input coupled to an output of the filter, the detector being configured to determine a hard decision and reliability of the filtered digital data signal;
• and
• a decoder having an input coupled to an output of the detector, the decoder being configured to decode the filtered digital data signal based at least in part on the hard decision and reliability;
• wherein the equalizer is configured:
• to receive the oversampled digital data signal comprising a first set of sampled digital data and a corresponding second set of sampled digital data, where samples in the first set of sampled digital data are offset from corresponding one of the samples in the second set of sampled digital data by a phase difference;
• and
• to combine one or more samples from the first set of sampled digital data with respective corresponding ones of the samples in the second set of sampled digital data to determine the equalized digital data signal.