Adaptive equalizer
AssigneeSanyo Electric Co., Ltd.
InventorOrimitsu Serizawa
Life of this patent
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Abstract
An adaptive equalizer comprising a variable filter which equalizes a digital input signal which is input in a time sequential order, an adaptive controller unit which updates a filter coefficient of the variable filter based on an output signal of the variable filter and the input signal and according to an equalization algorithm, and a coefficient resetting unit which resets a filter coefficient of the variable filter at a predetermined timing.
Claims9
An adaptive equalizer that adaptively equalizes a digital input signal input in a time sequential order, the adaptive equalizer comprising:
- a variable filter that equalizes the input signal;
- an adaptive controller unit that updates a filter coefficient of the variable filter based on an output signal of the variable filter and the input signal and according to an equalization algorithm;
- a coefficient determination unit that determines a filter coefficient of normal operation based on the filter coefficient updated by the adaptive controller unit;
- and
- a coefficient resetting unit that resets the filter coefficient of the variable filter to the filter coefficient of normal operation determined by the coefficient determination unit at a predetermined timing.
A digital signal replay device that replays digital data recorded on a recording medium, the digital signal replay device comprising:
- an adaptive equalizer that equalizes a replay signal of the digital data,
- wherein the adaptive equalizer comprises:
- a variable filter that equalizes the replay signal, which is digital and is input in a time sequential order;
- an adaptive controller unit that updates a filter coefficient of the variable filter based on an output signal of the variable filter and the replay signal and according to an equalization algorithm;
- a coefficient determination unit that determines a filter coefficient of normal operation based on the filter coefficient updated by the adaptive controller unit;
- and
- a coefficient resetting unit that resets the filter coefficient of the variable filter to the filter coefficient of normal operation determined by the coefficient determination unit at a predetermined timing.
A digital signal replay device that replays digital data recorded on a recording medium, the digital signal replay device comprising:
- an A/D converter that samples a replay signal of the digital data;
- an interpolator that estimates and interpolates a data value for a data point of the digital data based on a signal obtained from the A/D converter;
- and
- an adaptive equalizer that applies an equalization process on a signal obtained from the interpolator as an input signal and which feedbacks the equalized signal to the interpolator for the estimation and interpolation;
- wherein the adaptive equalizer comprises:
- a variable filter that equalizes the input signal which is digital and which is input in a time sequential order;
- an adaptive controller unit that updates a filter coefficient of the variable filter based on an output signal of the variable filter and the input signal and according to an equalization algorithm;
- a coefficient determination unit that determines a filter coefficient of normal operation based on the filter coefficient updated by the adaptive controller unit;
- and
- a coefficient resetting unit that resets the filter coefficient of the variable filter to the filter coefficient of normal operation determined by the coefficient determination unit at a predetermined timing;
- wherein the adaptive controller unit starts update of the filter coefficient after a position of estimation and interpolation by the interpolator approximately matches a data point of the digital data.
A computer readable medium containing instructions that allow a computer, in order to adaptively equalize a digital input signal input in a time sequential order, to function as:
- a variable filter that equalizes the input signal;
- an adaptive controller unit that updates a filter coefficient of the variable filter based on an output signal of the variable filter and the input signal and according to an equalization algorithm;
- a coefficient determination unit that determines a filter coefficient of normal operation based on the filter coefficient updated by the adaptive controller unit;
- and
- a coefficient resetting unit that resets a filter coefficient of the variable filter to the filter coefficient of normal operation determined by the coefficient determination unit at a predetermined timing.
An adaptive equalization method for adaptively equalizing a digital input signal input in a time sequential order, the method comprising:
- an equalization step of equalizing the input signal by a variable filter;
- an adaptive control step of updating a filter coefficient of the variable filter based on a signal obtained in the equalization step and the input signal and according to an equalization algorithm;
- a coefficient determination step of determining a filter coefficient of normal operation based on the filter coefficient updated in the adaptive control step;
- and
- a coefficient reset step of resetting a filter coefficient of the variable filter to the filter coefficient of normal operation determined in the coefficient determination step at a predetermined timing.
Dependencies are inferred from the claim text.