IP Library › Granted Patent US 7,158,567
Granted Patent B2
US 7,158,567 · App. 10/810,271 · Granted Jan 2, 2007

Method and apparatus for improved high-speed FEC adaptive equalization

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Quick Facts
Patent No.
US 7,158,567
App. No.
10/810,271
Granted
Jan 2, 2007
Kind
B2
Abstract

A method for performing adaptive equalization is presented comprising receiving a Forward Error Correction (FEC) encoded signal from a channel, filtering the received FEC encoded signal using a filter according to at least one adjustable filter coefficient to produce a filtered signal, evaluating the filtered signal to generate a signal error output, adjusting the at least one adjustable filter coefficient in response to the signal error output, performing FEC decode processing dependent on the filtered signal to generate an FEC output, and adjusting the at least one adjustable filter coefficient in response to the FEC output. In one embodiment, the signal error output relates to Mean Squared Error (MSE), and the FEC output relates to bit error rate. The at least one adjustable filter coefficient may be first adjusted in response to the signal error output until a specified condition is met, then adjusted in response to the FEC output.

Claims (63)

1. A method for performing adaptive equalization comprising:

receiving a Forward Error Correction (FEC) encoded signal from a channel;

filtering the received FEC encoded signal using a filter according to at least one adjustable filter coefficient to produce a filtered signal;

evaluating the filtered signal to generate a signal error output;

adjusting the at least one adjustable filter coefficient in response to the signal error output;

performing FEC decode processing dependent on the filtered signal to generate an FEC output;

adjusting the at least one adjustable filter coefficient in response to the FEC output;

wherein the at least one adjustable filter coefficient is first adjusted in response to the signal error output, then adjusted in response to the FEC output;

wherein the at least one adjustable filter coefficient is first adjusted in response to the signal error output until a specified condition is met, then adjusted in response to the FEC output; and

wherein the specified condition relates to an error measure varying less than a predetermined amount in N iterations of adjusting the at least one adjustable filter coefficient, where N is a positive integer.

2. The method of claim 1 wherein the signal error output relates to Mean Squared Error (MSE).

3. The method of claim 1 wherein the FEC output relates to bit error rate.

4. The method of claim 1 wherein the FEC output relates to bit error count.

5. The method of claim 1 wherein the at least one adjustable filter coefficient is selectively adjusted in response to the signal error output of the FEC output.

6. The method of claim 5 wherein the selective adjustment in response to the signal error output or the FEC output is selected based on a measurement of time-dependent variation of the channel.

7. A method for performing adaptive equalization comprising:

receiving a Forward Error Correction (FEC) encoded signal from a channel;

filtering the received FEC encoded signal using a filter according to at least one adjustable filter coefficient to produce a filtered signal;

evaluating the filtered signal to generate a signal error output;

adjusting the at least one adjustable filter coefficient in response to the signal error output;

performing FEC decode processing dependent on the filtered signal to generate an FEC output:

adjusting the at least one adjustable filter coefficient in response to the FEC output;

further comprising:

generating a plurality of symbols from the filtered signal based on a symbol decision clock and a symbol decision threshold, wherein the FEC decode processing is performed on the symbols;

adjusting the symbol decision clock in response to the signal error output; and

adjusting the symbol decision clock in response to the FEC output.

8. A method for performing adaptive equalization comprising:

receiving a Forward Error Correction (FEC) encoded signal from a channel;

filtering the received FEC encoded signal using a filter according to at least one adjustable filter coefficient to produce a filtered signal;

evaluating the filtered signal to generate a signal error output;

adjusting the at least one adjustable filter coefficient in response to the signal error output;

performing FEC decode processing dependent on the filtered signal to generate an FEC output;

adjusting the at least one adjustable filter coefficient in response to the FEC output;

further comprising generating a plurality of symbols from the filtered signal based on a symbol decision clock and a symbol decision threshold, wherein the FEC decode processing is performed on the symbols;

adjusting the symbol decision threshold in response to the signal error output; and

adjusting the symbol decision threshold in response to the FEC output.

9. An apparatus for performing adaptive equalization comprising:

a filter capable of filtering a Forward Error Correction (FEC) encoded signal received from channel according to at least one adjustable filter coefficient to produce a filtered signal;

an error detector adapted to evaluate the filtered signal to generate a signal error output;

an FEC decoder adapted to perform FEC decode processing dependent on the filtered signal to generate an FEC output;

a controller for adjusting the at least one adjustable filter coefficient in response to the signal error output and adjusting the at least one adjustable filter coefficient in response to the FEC output;

wherein the controller is adapted to first adjust the at least one adjustable filter coefficient in response to the signal error output, then adjust the at least one adjustable filter coefficient in response to the FEC output;

wherein the controller is adapted to first adjust the at least one adjustable filter coefficient in response to the signal error output until a specified condition is met, then adjust the at least one adjustable filter coefficient in response to the FEC output; and

wherein the specified condition relates to an error measure varying less than a predetermined amount in N iterations of adjusting the at least one adjustable filter coefficient, where N is a positive integer.

10. The apparatus of claim 9 wherein the signal error output relates to Mean Squared Error (MSE).

11. The apparatus of claim 9 wherein the FEC output relates to bit error rate.

12. The apparatus of claim 9 wherein the FEC output relates to bit error count.

13. The apparatus of claim 9 wherein the controller is adapted to selectively adjust the at least one adjustable filter coefficient in response to the signal error output or the FEC output.

14. The apparatus of claim 13 wherein the controller selects to adjust the at least one filter coefficient in response to the signal error output or the FEC output based on a measurement of time-dependent variation of the channel.

15. An apparatus for performing adaptive equalization comprising:

a filter capable of filtering a Forward Error Correction (FEC) encoded signal received from channel according to at least one adjustable filter coefficient to produce a filtered signal;

an error detector adapted to evaluate the filtered signal to generate a signal error output;

an FEC decoder adapted to perform FEC decode processing dependent on the filtered signal to generate an FEC output;

a controller for adjusting the at least one adjustable filter coefficient in response to the signal error output and adjusting the at least one adjustable filter coefficient in response to the FEC output;

further comprising a decision element for generating a plurality of symbols from the filtered signal based on a symbol decision clock and a symbol decision threshold, wherein the FEC decoder is adapted to perform FEC decode processing on the generated symbols; and

wherein the symbol decision clock is capable of being adjusting in response to the signal error output and adjusted in response to the FEC output.

16. An apparatus for performing adaptive equalization comprising:

a filter capable of filtering a Forward Error Correction (FEC) encoded signal received from channel according to at least one adjustable filter coefficient to produce a filtered signal;

an error detector adapted to evaluate the filtered signal to generate a signal error output;

an FEC decoder adapted to perform FEC decode processing dependent on the filtered signal to generate an FEC output;

a controller for adjusting the at least one adjustable filter coefficient in response to the signal error output and adjusting the at least one adjustable filter coefficient in response to the FEC output;

further comprising a decision element for generating a plurality of symbols from the filtered signal based on a symbol decision clock and a symbol decision threshold, wherein the FEC decoder is adapted to perform FEC decode processing on the generated symbols; and

wherein the symbol decision threshold is capable of being adjusted in response to the signal error output and adjusted in response to the FEC output.

Assignments (20)
RELEASE OF SECURITY INTEREST Recorded Mar 14, 2022
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
To: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 060894/0437 →
RELEASE OF SECURITY INTEREST Recorded Mar 11, 2022
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
To: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 059363/0001 →
RELEASE OF SECURITY INTEREST Recorded Mar 10, 2022
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
To: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 059863/0400 →
RELEASE OF SECURITY INTEREST Recorded Mar 9, 2022
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
To: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 059358/0001 →
RELEASE OF SECURITY INTEREST Recorded Feb 25, 2022
From: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
To: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 059333/0222 →
SECURITY INTEREST Recorded Jun 4, 2021
From: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
Reel/Frame 057935/0474 →
SECURITY INTEREST Recorded Dec 24, 2020
From: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 055671/0612 →
SECURITY INTEREST Recorded Jun 5, 2020
From: MICROCHIP TECHNOLOGY INC.; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: WELLS FARGO BANK, NATIONAL ASSOCIATION
Reel/Frame 053468/0705 →
RELEASE OF SECURITY INTEREST Recorded May 30, 2020
From: JPMORGAN CHASE BANK, N.A, AS ADMINISTRATIVE AGENT
To: MICROCHIP TECHNOLOGY INC.; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 053466/0011 →
SECURITY INTEREST Recorded Apr 24, 2020
From: MICROCHIP TECHNOLOGY INC.; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 053311/0305 →
SECURITY INTEREST Recorded Sep 18, 2018
From: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS NOTES COLLATERAL AGENT
Reel/Frame 047103/0206 →
SECURITY INTEREST Recorded Jun 25, 2018
From: MICROCHIP TECHNOLOGY INCORPORATED; SILICON STORAGE TECHNOLOGY, INC.; ATMEL CORPORATION; MICROSEMI CORPORATION; MICROSEMI STORAGE SOLUTIONS, INC.
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 046426/0001 →
RELEASE OF SECURITY INTEREST Recorded May 29, 2018
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: MICROSEMI CORPORATION; MICROSEMI SEMICONDUCTOR (U.S.), INC.; MICROSEMI FREQUENCY AND TIME CORPORATION; MICROSEMI COMMUNICATIONS, INC.; MICROSEMI SOC CORP.; MICROSEMI CORP. - POWER PRODUCTS GROUP; MICROSEMI CORP. - RF INTEGRATED SOLUTIONS
Reel/Frame 046251/0391 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 22, 2017
From: MICROSEMI COMMUNICATIONS, INC.
To: MICROSEMI STORAGE SOLUTIONS, INC.
Reel/Frame 042523/0577 →
PATENT SECURITY AGREEMENT Recorded Feb 3, 2016
From: MICROSEMI CORPORATION; MICROSEMI SEMICONDUCTOR (U.S.) INC. (F/K/A LEGERITY, INC., ZARLINK SEMICONDUCTOR (V.N.) INC., CENTELLAX, INC., AND ZARLINK SEMICONDUCTOR (U.S.) INC.); MICROSEMI FREQUENCY AND TIME CORPORATION (F/K/A SYMMETRICON, INC.); MICROSEMI COMMUNICATIONS, INC. (F/K/A VITESSE SEMICONDUCTOR CORPORATION); MICROSEMI SOC CORP. (F/K/A ACTEL CORPORATION); MICROSEMI CORP. - POWER PRODUCTS GROUP (F/K/A ADVANCED POWER TECHNOLOGY INC.); MICROSEMI CORP. - RF INTEGRATED SOLUTIONS (F/K/A AML COMMUNICATIONS, INC.)
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 037691/0697 →
RELEASE OF SECURITY INTEREST Recorded Jan 19, 2016
From: BANK OF AMERICA, N.A.
To: MICROSEMI CORPORATION; MICROSEMI CORP.-ANALOG MIXED SIGNAL GROUP, A DELAWARE CORPORATION; MICROSEMI SOC CORP., A CALIFORNIA CORPORATION; MICROSEMI SEMICONDUCTOR (U.S.) INC., A DELAWARE CORPORATION; MICROSEMI FREQUENCY AND TIME CORPORATION, A DELAWARE CORPORATION; MICROSEMI COMMUNICATIONS, INC. (F/K/A VITESSE SEMICONDUCTOR CORPORATION), A DELAWARE CORPORATION; MICROSEMI CORP.-MEMORY AND STORAGE SOLUTIONS (F/K/A WHITE ELECTRONIC DESIGNS CORPORATION), AN INDIANA CORPORATION
Reel/Frame 037558/0711 →
MERGER AND CHANGE OF NAME Recorded May 13, 2015
From: VITESSE SEMICONDUCTOR CORPORATION; LLIU100 ACQUISITION CORP.
To: MICROSEMI COMMUNICATIONS, INC.
Reel/Frame 035651/0708 →
SUPPLEMENTAL SECURITY AGREEMENT Recorded Apr 29, 2015
From: MICROSEMI COMMUNICATIONS, INC.
To: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
Reel/Frame 035532/0925 →
RELEASE OF SECURITY INTEREST Recorded Apr 28, 2015
From: WHITEBOX VSC, LTD.
To: VITESSE SEMICONDUCTOR CORPORATION
Reel/Frame 035526/0090 →
RELEASE OF SECURITY INTEREST Recorded Nov 5, 2014
From: US BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: VITESSE SEMICONDUCTOR CORPORATION
Reel/Frame 034176/0162 →