Nonlinear equalizer and decoding circuit and method using same
AssigneeInternational Business Machines Corporation
InventorConstantin Michael Melas
Life of this patent
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Abstract
A decoding circuit has a nonlinear equalizer which employs a signal conditioning algorithm for conditioning a partial response sampled signal to eliminate intersymbol interference. The inventive decoding circuit has an analog-to-digital converter for sampling an analog signal, a linear equalizer for adjusting the amplitude and phase relations of the sampled signal, a nonlinear equalizer for conditioning the sampled signal and outputting a partial response sampled signal having two nonzero samples, and a partial response maximum likelihood detector, for detecting the partial response sampled signal having two nonzero samples.
Claims22
A nonlinear equalizer employing a signal conditioning algorithm for conditioning a partial response sampled signal having four nonzero samples into a partial response sampled signal having two nonzero samples.
A decoding circuit comprising:
- an analog-to-digital converter for sampling an analog signal and outputting a partial response sampled signal having four nonzero samples;
- a linear equalizer for adjusting an amplitude and phase relations of said partial response sampled signal having four nonzero samples;
- a nonlinear equalizer for conditioning said partial response sampled signal having four nonzero samples and outputting a partial response sampled signal having two nonzero samples;
- and
- a partial response maximum likelihood detector, for detecting said partial response sampled signal having two nonzero samples.
A method for recovering information coded onto an analog signal and recorded onto a tracked storage medium, said method comprising:
- sampling said analog signal to produce a partial response sampled signal having a sequence of four non-zero samples S1, S2, S3, S4;
- conditioning said partial response sampled signal according to a signal conditioning algorithm to produce a three level signal;
- detecting said three level signal using a partial response maximum likelihood detector;
- and
- decoding said three level signal to produce a decoded data signal.
A magnetic recording system comprising a decoding circuit for decoding a read signal, said decoding circuit comprising:
- an analog-to-digital converter for sampling an analog signal and outputting a partial response sampled signal having four nonzero samples;
- a linear equalizer for adjusting an amplitude and phase relations of said partial response sampled signal having four nonzero samples;
- a nonlinear equalizer for conditioning said partial response sampled signal having four nonzero samples and outputting a partial response sampled signal having two nonzero samples;
- and
- a partial response maximum likelihood detector, for detecting said partial response sampled signal having two nonzero samples.
A digital detection channel comprising:
- an analog-to-digital converter for sampling an analog signal and outputting a partial response sampled signal having four nonzero samples;
- a linear equalizer for adjusting an amplitude and phase relations of said partial response sampled signal having four nonzero samples;
- a nonlinear equalizer for conditioning said sampled signal and outputting a partial response sampled signal having two nonzero samples;
- and
- a partial response maximum likelihood detector, for detecting said partial response sampled signal having two nonzero samples.
A programmable storage medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform method for recovering information coded onto an analog signal and recorded onto a tracked storage medium, said method comprising:
- sampling said analog signal to produce a partial response sampled signal having a sequence of four non-zero samples S1, S2, S3, S4;
- conditioning said partial response sampled signal according to a signal conditioning algorithm to produce a three level signal;
- detecting said three level signal using a partial response maximum likelihood detector;
- decoding said three level signal to produce a decoded data signal.
Dependencies are inferred from the claim text.