Receive equalizer with adaptive loops
First Claim
Patent Images
1. A data communication system comprising:
- an input for receiving a signal;
a first control loop configured to perform a square error calculation on data associated with the received signal and configured to adjust the received signal in accordance with the square error; and
a second control loop configured to optimize sampling of the data in accordance with a comparison of data from two different paths.
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Abstract
A communication receiver includes a decision feedback equalizer and clock and data recovery circuit. Various adaptation loops may control the operation of the decision feedback equalizer, the clock and data recovery circuit, a continuous time filter, a threshold adjust circuit, and an analog-to-digital clock that is used to generate soft decision data for some of the adaptation loops.
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Citations
51 Claims
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1. A data communication system comprising:
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an input for receiving a signal;
a first control loop configured to perform a square error calculation on data associated with the received signal and configured to adjust the received signal in accordance with the square error; and
a second control loop configured to optimize sampling of the data in accordance with a comparison of data from two different paths. - View Dependent Claims (2, 3, 4, 5)
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6. A method of adjusting a received signal comprising:
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receiving a signal;
sampling the received signal to generate data associated with the received signal;
performing a square error calculation in accordance with the data;
adjusting the received signal in accordance with the square error calculation; and
optimizing the sampling of the data in accordance with a comparison of data from two different paths. - View Dependent Claims (7, 8, 9, 10)
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11. A communications system comprising:
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a decision feedback equalizer adapted to reduce channel related distortion in a received signal in accordance with a least mean square adaptation loop; and
a relative error adaptation loop adapted to optimize data for the least mean square adaptation loop in accordance with a comparison of data from two different data paths. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A communications system comprising:
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a mean square error adaptation loop configured to adjust a received signal in accordance with a mean square error adaptation loop; and
a relative error adaptation loop adapted to optimize data for the mean square error adaptation loop in accordance with a comparison of data from two different data paths. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A communications system comprising:
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a decision feedback equalizer adapted to reduce channel related distortion in a received signal in accordance with a least mean square adaptation loop; and
a threshold adjust loop adapted to adjust a DC component of the received signal in accordance with tail distribution data. - View Dependent Claims (26, 27, 28)
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29. A communications system comprising:
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a mean square error adaptation loop configured to adjust a received signal in accordance with a mean square error associated with the received signal; and
a threshold adjust loop adapted to adjust a DC component of the received signal in accordance with tail distribution data. - View Dependent Claims (30, 31)
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32. A communications system comprising:
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an automatic gain control circuit for amplifying a received signal;
a continuous time filter for filtering the amplified signal in accordance with a mean square error adaptation loop;
a decision feedback equalizer adapted to reduce channel related distortion in the filtered signal in accordance with a least mean square adaptation loop;
a clock and data recovery circuit adapted to recover a clock signal from the equalized signal;
a delay lock loop for generating a sampling clock for generating data for the adaptation loops; and
a relative error adaptation loop adapted to adjust a phase of the sampling clock in accordance with a comparison of data from two different data paths.
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33. A communications system comprising:
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an automatic gain control circuit for amplifying a received signal;
a continuous time filter for filtering the amplified signal in accordance with a mean square error adaptation loop a threshold adjust loop adapted to adjust a DC component of the filtered signal in accordance with tail distribution data;
a decision feedback equalizer adapted to reduce channel related distortion in the threshold adjusted signal in accordance with a least mean square adaptation loop;
a clock and data recovery circuit adapted to recover a clock signal from the equalized signal; and
a delay lock loop for generating a sampling clock for generating data for the adaptation loops. - View Dependent Claims (34, 35, 36)
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37. A communication receiver comprising:
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an automatic gain control circuit for amplifying a received signal;
a continuous time filter for filtering the amplified signal in accordance with at least one filter coefficient generated by at least one adaptation loop;
a threshold adjust loop adapted to adjust a DC component of the filtered signal in accordance with tail distribution data generated by the at least one adaptation loop;
a decision feedback equalizer adapted to reduce channel related distortion in the threshold adjusted signal, the decision feedback equalizer comprising;
a summer that combines the received signal with at least one equalized feedback signal generated by the at least one adaptation loop to generate a soft decision signal;
a slicer coupled to the summer, wherein the slicer converts the soft decision signal to a binary signal; and
a retimer coupled to the slicer, wherein the retimer generates detected data signals from the binary signal in response to an extracted clock signal;
a clock and data recovery circuit configured to generate the extracted clock signal from the binary signal and at least a portion of the detected data signals, the clock and data recovery circuit comprising a phase adjust circuit adapted to adjust a phase of the extracted clock signal in accordance with at least one phase coefficient generated by the at least one adaptation loop;
a delay lock loop for generating a sampling clock signal from the extracted clock signal;
a relative error adaptation loop adapted to adjust a phase of the sampling clock signal in accordance with a comparison of data from two different data paths; and
an analog to digital converter, clocked by the adjusted sampling clock signal, for sampling the soft decision signal to generate data for the at least one adaptation loop. - View Dependent Claims (38, 39, 40, 41, 42, 43)
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44. A method of providing a stable multiple loop system comprising:
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providing a first adaptation loop based on a square error criteria; and
providing a second adaptation loop based on a tail distribution criteria. - View Dependent Claims (45, 46, 47)
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48. A method of providing a stable multiple loop system comprising:
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providing a first adaptation loop based on a square error criteria; and
providing a second adaptation loop based on a relative error criteria. - View Dependent Claims (49, 50, 51)
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Specification