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US 9,544,170 B2Granted
Methods and circuits for adaptive equalization
AssigneeRambus Inc.
InventorRamin Farjad-Rad
Life of this patent
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Abstract
An integrated circuit equalizes a data signal expressed as a series of symbols. The symbols form data patterns with different frequency components. By considering these patterns, the integrated circuit can experiment with equalization settings specific to a subset of the frequency components, thereby finding an equalization control setting that optimizes equalization. Optimization can be accomplished by setting the equalizer to maximize symbol amplitude.
Claims20
A receiver to recover a signal having low-frequency components and high-frequency components, the receiver comprising:
- an adaptive equalizer to attenuate the low-frequency components with respect to the high-frequency components of the signal, thereby producing an equalized, reduced inter-symbol interference (ISI) version of the signal;
- at least one sampler to sample the reduced ISI version of the signal, the at least one sampler producing symbols responsive to the reduced ISI version of the signal;
- a data filter to identify a transition between adjacent ones of a series of the symbols, the transition occurring immediately subsequent a pattern of preceding symbols without transition;
- and
- adaptive control circuitry to adjust the adaptive equalizer responsive to the symbol immediately subsequent the pattern of preceding symbols without transition.
2 more elements
A method comprising:
- equalizing a data signal using an equalization setting to produce an equalized signal having low-frequency components and high-frequency components, the data signal representing a series of symbols;
- sampling the series of symbols to produce a series of samples of alternative first and second sample types, each sample representing a value of the corresponding one of the symbols;
- monitoring the series of samples for consecutive samples of the first sample type followed by a transition to a sample of the second sample type;
- and
- varying a degree to which the equalizing of the data signal amplifies the high-frequency components relative to the low-frequency components responsive to the one of the series of symbols corresponding to the sample of the second sample type immediately following the transition.
2 more elements
A receiver comprising:
- an equalizer to equalize a data signal, using an equalization setting, to produce an equalized signal, the equalized signal including a series of symbols, each symbol having a symbol amplitude and representing alternative first and second symbol values;
- a pattern detector to detect a patterns of the symbol values, each pattern including sequential symbols of the first symbol value and a transition to a symbol of the second symbol value;
- and
- means for adjusting the equalizer responsive to the amplitudes of the symbols of the second symbol value.
1 more element
Dependencies are inferred from the claim text.