US 11,153,135 B1Granted

Methods and systems for adaptive equalization with wide range of signal amplitudes

AssigneeTexas Instruments Incorporated

InventorsShita Guo, Yanli Fan, Mustafa Ulvi Erdogan, Douglas Edward Wente

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Abstract

Methods and systems of adaptive equalization to compensate channel loss are disclosed. A method includes detecting a peak amplitude of an equalizer output signal and selecting a set of reference voltage levels from M sets based on the peak amplitude of the equalizer output signal, each of the M sets having N reference voltage levels. The method includes continuing to increase an equalization level in predetermined steps to a next higher equalization level if the applied equalization level does not correspond to the over-equalization level and evaluating the distribution of the resulting hit counts for each increase to the next higher equalization level until the applied equalization level corresponds to the over-equalization level. The method includes decreasing to the previously applied lower equalization level if the applied equalization level corresponds to the over-equalization level.

Claims18

Dependent claims

A method of adaptive equalization, comprising:

detecting a peak amplitude of an equalizer output signal;
selecting a set of reference voltage levels from M sets based on the peak amplitude of the equalizer output signal, each of the M sets having N reference voltage levels;
initially applying zero equalization to generate the equalizer output signal and comparing the equalizer output signal to the N reference voltage levels of the selected set;
generating hit counts responsive to the comparison of the equalizer output signal to the N reference voltage levels;
increasing from zero equalization to a first equalization level and applying the first equalization level to generate hit counts responsive to the comparison of the equalizer output signal to the N reference voltage levels, and evaluating the distribution of resulting hit counts to determine if the applied equalization level corresponds to an over-equalization level;
if the applied equalization level corresponds to the over-equalization level, decreasing to the previously applied lower equalization level, wherein the previously applied lower equalization level corresponds to an optimal equalization level;
if the applied equalization level does not correspond to the over-equalization level, continuing to increase the equalization level in predetermined steps to a next higher equalization level and evaluating the distribution of the resulting hit counts for each increase to the next higher equalization level until the applied equalization level corresponds to the over-equalization level, and decreasing to the previously applied lower equalization level if the applied equalization level corresponds to the over-equalization level.

4 more elements

An adaptive equalization system, comprising:

an equalizer having a first input configured to receive an input signal and a second input configured to receive a boost control signal and an output configured to provide an equalizer output signal;
a peak detector circuit having an input configured to receive the equalizer output signal and an output configured to provide an analog peak detection signal indicating the peak amplitude of the equalizer output signal;
an analog-to-digital converter having an input configured to receive the analog peak detection signal and an output configured to provide a digital peak detection signal;
a digital-to-analog converter having a first input configured to receive a reference voltage level control signal and a second input configured to receive the digital peak detection signal and an output configured to provide a reference voltage;
a comparison circuit having a first input configured to receive the equalizer output signal and a second input configured to receive the reference voltage and an output configured to provide a comparison signal;
and
an equalizer control circuit having an input configured to receive the comparison signal and a first output configured to provide the boost control signal and a second output configured to provide the reference voltage level control signal.

4 more elements

A method of adaptive equalization comprising:

detecting a peak amplitude of an equalizer output signal;
selecting a set of reference voltage levels from M sets based on the peak amplitude of the equalizer output signal, each of the M sets having N reference voltage levels, wherein the reference voltage level having the highest value in the selected set is greater than the peak amplitude of the equalizer output signal;
initially applying zero equalization to generate the equalizer output signal and comparing the equalizer output signal to the N reference voltage levels of the selected set;
generating hit counts responsive to the comparison of the equalizer output signal to the N reference voltage levels;
increasing from zero equalization to a first equalization level and applying the first equalization level to generate hit counts responsive to the comparison of the equalizer output signal to the N reference voltage levels, and evaluating the distribution of resulting hit counts to determine if the applied equalization level corresponds to an over-equalization level;
if the applied equalization level corresponds to the over-equalization level, decreasing to the previously applied lower equalization level, wherein the previously applied lower equalization level corresponds to an optimal equalization level;
if the applied equalization level does not correspond to the over-equalization level, continuing to increase the equalization level in predetermined steps to a next higher equalization level and evaluating the distribution of the resulting hit counts for each increase to the next higher equalization level until the applied equalization level corresponds to the over-equalization level, and decreasing to the previously applied lower equalization level if the applied equalization level corresponds to the over-equalization level,
wherein the hit counts are generated responsive to intersections of the equalizer output signal and the compared reference voltage levels, and
wherein the applied equalization level corresponds to the over-equalization level if the distribution of the hit counts indicates overshoots and undershoots.

6 more elements

Dependencies are inferred from the claim text.