US 9,853,839 B2 · System, method and software program for tuneable equalizer adaptation using sample interpolation

Abstract

Various embodiments of the present invention solve the problem of generating intermediate-time information useable to drive ZFE adaptation (for example, in connection with a digital receiver). Further, various embodiments of the present invention increase flexibility by enabling user-specified over-peaking and/or under-peaking (i.e. configurable equalizer tuning) with respect to a ZFE convergence (or lock) criterion.

Drawings

Claims20

Dependent claims

A system, comprising:

an analog continuous-time equalizer, the analog continuous-time equalizer being configured to obtain data in the form of an analog signal;
an analog-to-digital converter in operative communication with the analog continuous-time equalizer, the analog-to-digital converter being configured to receive an output from the analog continuous-time equalizer;
a feed-forward equalizer in operative communication with the analog-to-digital converter, the feed-forward equalizer being configured to receive an output from the analog-to-digital converter;
a first buffer in operative communication with the feed-forward equalizer, the first buffer being configured to capture an output of the feed-forward equalizer;
an interpolator in operative communication with the first buffer, the interpolator being configured to receive an output from the first buffer;
a second buffer, the second buffer being configured to capture one of:
(a) the output of the feed-forward equalizer via operative communication with the feed-forward equalizer;
and (b) data based upon the output of the feed-forward equalizer;
a zero-force edge calculator in operative communication with the interpolator, the second buffer and the analog continuous-time equalizer, the zero-force edge calculator being configured to receive an output from the interpolator and an output from the second buffer, the zero-force edge calculator being further configured to feed back continuous-time equalizer adaptation data to the analog continuous-time equalizer;
wherein the continuous-time equalizer adaptation data fed back by the zero-force edge calculator to the analog continuous-time equalizer is based at least in part upon the output from the interpolator and the second buffer.

7 more elements

A method, comprising:

receiving data in the form of an analog signal;
applying the received data to an analog continuous-time equalizer process;
applying an output of the analog continuous-time equalizer process to an analog-to-digital converter process;
applying an output of the analog-to-digital converter process to a feed-forward equalizer process;
capturing an output of the feed-forward equalizer process in a first buffer process;
applying an output of the first buffer process to an interpolation process;
capturing in a second buffer process one of:
(a) an output of the feed-forward process;
and (b) an output of another process based upon the output of the feed-forward process;
applying an output of the interpolation process to a zero-force edge process;
applying an output of the second buffer process to the zero-force edge process;
and
feeding back at least part of an output of the zero-force edge process to the analog continuous-time equalizer process.

10 more elements

A non-transitory computer-readable storage device having stored thereon computer-readable instructions that, when executed by a computer, implement:

receiving data in the form of an analog signal;
applying the received data to an analog continuous-time equalizer process;
applying an output of the analog continuous-time equalizer process to an analog-to-digital converter process;
applying an output of the analog-to-digital converter process to a feed-forward equalizer process;
capturing an output of the feed-forward equalizer process in a first buffer process;
applying an output of the first buffer process to an interpolation process;
capturing in a second buffer process one of:
(a) an output of the feed-forward process;
and (b) an output of another process based upon the output of the feed-forward process;
applying an output of the interpolation process to a zero-force edge process;
applying an output of the second buffer process to the zero-force edge process;
and
feeding back at least part of an output of the zero-force edge process to the analog continuous-time equalizer process.

10 more elements

Dependencies are inferred from the claim text.

Description6,546 words

Summary824 words

#In a conventional digital receiver system which samples data at a given BAUD rate (once per symbol transmission interval), there is no intermediate-time information available to adapt an analog continuous-time equalizer (“CTE”) and/or feed-forward equalizer (“FFE”) according to an optimal zero-force edge (“ZFE”) convergence (or lock) criterion.

#Various embodiments of the present invention solve the problem of generating intermediate-time information useable to drive ZFE adaptation. Further, various embodiments of the present invention increase flexibility by enabling user-specified over-peaking and/or under-peaking (i.e. configurable equalizer tuning) with respect to the ZFE convergence (or lock) criterion.

#T. Toifl et. al. (“Low Complexity Adaptive Equalization for High-Speed Chip-to-Chip Communication Paths by Zero-Forcing of Jitter Components”, IEEE Trans. Commun. vol. 54, no. 9, September 2006 pp. 1554-57) describes the basic concept of zero-forcing of jitter components by adapting a feed-forward equalizer.

Brief description of the drawings9 figures

#The drawings are provided for illustrative purpose only and do not necessarily represent practical examples of the present invention to scale.

#FIG. 1 shows a block diagram of a digital receiver system providing an example implementation according to an embodiment of the present invention.

#FIG. 2A shows a graph of an example fractional delay interpolator frequency response according to an embodiment of the present invention and FIG. 2B shows a corresponding example sixth order fractional delay interpolation polynomials used for the graph of FIG. 2A.

Detailed description5,486 words

#One embodiment of the present invention relates to a system for tuneable equalizer adaptation using sample interpolation. Another embodiment of the present invention relates to a method for tuneable equalizer adaptation using sample interpolation. Another embodiment of the present invention relates to a software program for tuneable equalizer adaptation using sample interpolation.

#Various embodiments of the present invention are based upon the observation that the zero-forcing of jitter components is equivalent to decorrelating ISI that arises from a data bit and appears at an edge crossover position at, for example, 1.5 unit intervals (“UI”) delayed (from the data bit).

#In various embodiments, the intermediate sample position data at the 1.5 unit interval delay is estimated using interpolation polynomials applied to the sampled data (i.e., the received data after analog-to-digital conversion). The sampled data is measured at discrete unit intervals with a time period “T” corresponding to an ADC sample rate of FS=1.0/T samples/sec.

Facts

Application

15/164,162Filed 25 May 2016

Published

US 2017/0346662 A130 Nov 2017

Granted

26 Dec 2017

Term ends

25 May 2036

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification8 codes

H04L 25/03019
Operating in the time domain: adaptive, i.e. capable of adjustment during data reception
H03M 1/12
Analogue/digital conversion; Digital/analogue conversion: analogue/digital converters
H04L 7/002
Correction of synchronization errors: correction by interpolation
H04L 25/03057
Adaptive, i.e. capable of adjustment during data reception: with a recursive structure

Timeline

25 May 2016Application filedUS 15/164,162
20 Nov 2017Assigned to Globalfoundries Inc.assignment of assignor's interest
30 Nov 2017PublishedUS 2017/0346662 A1
26 Dec 2017GrantedUS 9,853,839 B2
29 Nov 2018Assigned to Wilmington Trust, National Associationsecurity agreement
2 Nov 2020Assigned to Globalfoundries U.S. Inc.assignment of assignor's interest
20 Nov 2020Assigned to Globalfoundries Inc.release of security interest
12 May 2021Assigned to Globalfoundries U.S. Inc.release of security interest
12 Oct 2026TodayWithin its term
25 May 2036Term endsEstimated

System, method and software program for tuneable equalizer adaptation using sample interpolation

Life of this patent

System, method and software program for tuneable equalizer adaptation using sample interpolation

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims20

Description6,546 words

Drawings

Classification8 codes

Life of this patent

Description6,546 words