Disk drive employing general noise whitening filter to reduce length of data dependent noise whitening filters
AssigneeWestern Digital Technologies, Inc.
InventorsPatrick J. Lee, Manmohan K. Sharma
Life of this patent
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Abstract
A disk drive is disclosed comprising a head actuated over a disk, wherein data is read from the disk to generate a read signal. The read signal is sampled to generate signal samples, and the signal samples are filtered with an equalizer filter to generate equalized samples. The equalized samples are filtered with a general noise whitening filter to generate general noise whitened samples. The general noise-whitened samples are filtered with a bank of data dependent noise whitening filters to generate data dependent noise whitened samples, and a data sequence is detected from the data dependent noise whitened samples.
Claims6
A disk drive comprising:
- a disk;
- a head actuated over the disk;
- and
- control circuitry operable to:
- read data from the disk to generate a read signal;
- sample the read signal to generate signal samples;
- filter the signal samples with an equalizer filter to generate equalized samples;
- filter the equalized samples with a general noise whitening filter independent of any data pattern generated by a sequence detector to generate general noise whitened samples;
- filter the general noise-whitened samples with a bank of data dependent noise whitening filters to generate data dependent noise whitened samples;
- and
- detect a data sequence from the data dependent noise whitened samples.
A method of operating a disk drive comprising a head actuated over a disk, the method comprising:
- reading data from the disk to generate a read signal;
- sampling the read signal to generate signal samples;
- filtering the signal samples with an equalizer filter to generate equalized samples;
- filtering the equalized samples with a general noise whitening filter independent of any data pattern generated by a sequence detector to generate general noise whitened samples;
- filtering the general noise-whitened samples with a bank of data dependent noise whitening filters to generate data dependent noise whitened samples;
- and
- detecting a data sequence from the data dependent noise whitened samples.
Dependencies are inferred from the claim text.