Error propagation control method in decision feedback equalization and magnetic recording/reproducing device
AssigneeFujitsu Limited
InventorHiroaki Ueno
Life of this patent
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Abstract
An error propagation control method and a recording/reproducing device which uses the method in a system which makes use of MDFE are disclosed. In the error propagation control method in accordance with multi-level decision feedback equalization in which the input to the detector is fed back to the input side via the feedback filter and the difference between the input signal and the feedback signal is input to the detector, the error propagation state is detected based on the output of the detector. Based on the error propagation detection result, a predetermined offset is added to the slice level of the detector, DC offset is added to the DC level of the input signal of the detector, or a sign of the tap of the feedback filter is reversed.
Claims24
An error propagation control method based on decision feedback equalization comprising the steps of:
- outputting the difference or sum of an input signal and a feedback signal;
- detecting a level for said output difference or sum with reference to a slice level;
- feeding back said detected level as the feedback signal to an input signal side;
- deciding an error propagation state of said input signal, based on said detected level;
- and
- adding a predetermined offset to said slice level based on said decided error propagation state.
An error propagation control method based on decision feedback equalization comprising the steps of:
- outputting the difference or sum of an input signal and a feedback signal;
- detecting a level for said output difference or sum with reference to a slice level;
- feeding back said detected level as the feedback signal to an input signal side;
- deciding an error propagation state of said input signal based on said detected level;
- and
- adding a predetermined DC offset to a DC level of said input signal for which the level is detected with reference to the slice level, based on said decided error propagation state.
An error propagation control method based on decision feedback equalization comprising the steps of:
- outputting the difference or sum of an input signal and a feedback signal;
- detecting a level for said output difference or sum with reference to a slice level;
- feeding back said detected level as the feedback signal to an input signal side;
- deciding an error propagation state of said input signal based on said detected level;
- and
- reversing the sign of a tap of a feedback filter which feeds back said decided level to said input signal side, based on said decided error propagation state.
A magnetic reproducing circuit comprising:
- an input circuit for outputting the difference or sum of an input signal read from a magnetic recording medium and a feedback signal;
- a detector for deciding a positive or negative polarity of the output difference or sum of the input signal and the feedback signal with reference to a slice level;
- a feedback filter for feeding back to the input circuit a sum obtained by multiplying a predetermined coefficient to the output of said detector as the feedback signal;
- and
- a slice offset control part for adding a predetermined offset to the slice level of said detector based on an error propagation state of said input signal.
A magnetic reproducing circuit comprising:
- an input circuit for outputting the difference or sum of an input signal read from a magnetic recording medium and a feedback signal;
- a detector for deciding a positive or negative polarity of the output difference or sum with reference to a slice level;
- a feedback filter for feeding back to the input circuit a sum obtained by multiplying a predetermined coefficient to the output of said detector as the feedback signal;
- and
- a DC offset control part for adding a DC offset to a DC level of the output from the input circuit, based on an error propagation state of said input signal.
A magnetic reproducing circuit comprising:
- an input circuit for outputting the difference or sum of an input signal read from a magnetic recording medium and a feedback signal;
- a detector for deciding a positive or negative polarity of the output difference or sum with reference to a slice level;
- a feedback filter for feeding back to the input circuit a sum obtained by multiplying a predetermined coefficient to the output of said detector as the feedback signal;
- and
- a control part for reversing the sign of a tap of said feedback filter based on an error propagation state of said input signal.
Dependencies are inferred from the claim text.