ADAPTABLE FORWARD ERROR CORRECTION

• US 20190044654A1
• Filed: 08/03/2017
• Published: 02/07/2019
• Est. Priority Date: 08/03/2017
• Status: Active Grant

• Current Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Original Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Inventors: Schmidtke, Hans-Juergen, Lyubomirsky, Ilya
• Granted Patent: US 10,574,391 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 10/07953 Monitoring or measuring OSNR, BER or Q
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/005 Iterative decoding, including iteration between signal detection and decoding operation
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER

Abstract

Optical fiber data communications are described. An error correction circuit can receive a signal and correct bit errors of that signal. The circuit can then determine characteristics of the signal (e.g., its bit error rate (BER)) and adjust the operations performed to correct the bit errors of the signal based on the characteristics.

Claims

1. An optical fiber data communications system, comprising:

a first forward error correction (FEC) circuit configured to receive a first signal and determine first characteristics of the first signal, and the first FEC circuit configured to determine first operational parameters representing functionality performed on the first signal by the first FEC based on the first characteristics; and

a second FEC circuit configured to receive a second signal and determine second characteristics of the second signal, and the second FEC circuit configured to determine second operational parameters representing functionality performed on the second signal by the second FEC based on the second characteristics, the first characteristics and the second characteristics being different, and the functionality performed on the first signal and the second signal being different.

2. The optical fiber data communications system of claim 1, wherein the first FEC circuit implements Reed-Solomon error correction, and the second FEC circuit also implements Reed-Solomon error correction.

3. The optical fiber data communications system of claim 1, wherein the functionality performed on the first signal includes a first number of decoding iterations to correct bit errors of the first signal, and the functionality performed on the second signal includes a second number of decoding iterations to correct bit errors of the second signal, the first number and the second number being different numbers.

4. The optical fiber data communications system of claim 1, wherein the functionality performed on the first signal includes selecting a first block size representing a first number of bits to be analyzed at a time to correct bit errors, the functionality performed on the second signal includes selecting a second block size representing a second number of bits to be analyzed at a time to correct bit errors, the first block size and the second block size being different sizes.

5. The optical fiber data communications system of claim 1, wherein the first characteristics includes a bit error rate (BER) of the first signal, and the second characteristics includes a BER of the second signal.

6. The optical fiber data communications system of claim 5, wherein the BER of the first signal is different than the BER of the second signal, and the first operational parameters and the second operational parameters are different based on the BER of the first signal being different than the BER of the second signal.

7. The optical fiber data communications system of claim 5, wherein the BER of the first signal is higher than the BER of the second signal, and the first operational parameters are representative of the first FEC circuit performing more decoding iterations to correct bit errors than the second FEC circuit.

8. The optical fiber data communications system of claim 5, wherein the BER of the first signal is higher than the BER of the second signal, and the first operational parameters are representative of the first FEC circuit providing functionality corresponding to a higher coding gain than the second FEC circuit.

9. The optical fiber data communications system of claim 1, wherein the first characteristics includes a signal-to-noise ratio (SNR) of the first signal, and the second characteristics includes a SNR of the second signal.

10. The optical fiber data communications system of claim 9, wherein the SNR of the first signal is different than the SNR of the second signal, and the functionality performed on the first signal and the second signal being different is based on the SNR of the first signal being different than the SNR of the second signal.

11. An error correction circuit configured to receive a signal and correct bit errors of the signal based on first operations performed to correct the bit errors, configured to determine characteristics of the signal, and configured to adjust operations performed from the first operations to second operations to correct the bit errors based on the characteristics of the signal, the first operations and the second operations being different.

12. The error correction circuit of claim 11, wherein the characteristics include bit error rate (BER) of the signal.

13. The error correction circuit of claim 11, wherein the characteristics include a signal-to-noise ratio (SNR) of the signal.

14. The error correction circuit of claim 11, wherein the second operations have lower power consumption than the first operations.

15. The error correction circuit of claim 11, wherein the bit errors are corrected based on Reed-Solomon error correction.

16. The error correction circuit of claim 11, wherein the first operations include performing a first number of decoding iterations to correct the bit errors of the signal, and the second operations include performing a second number of decoding iterations to correct the bit errors of the signal, the first number and the second number being different numbers.

17. A method, comprising:

performing error correction on a signal based on first operational parameters representing first functionality performed on the signal;

determining characteristics of the signal;

determining second operational parameters representing second functionality to perform on the signal based on the characteristics of the signal, the first functionality and the second functionality being different functionalities; and

adjusting performance of the error correction to perform the second functionality rather than the first functionality.

18. The method of claim 17, wherein the characteristics of the signal include a bit error rate (BER) of the signal.

19. The method of claim 17, wherein the first functionality includes performing a first number of decoding iterations to correct bit errors of the signal, and the second functionality includes performing a second number of decoding iterations to correct bit errors of the signal, the first number and the second number being different numbers.

20. The method of claim 17, wherein the characteristics of the signal include a signal-to-noise ratio (SNR) of the signal.