Echo cancellation to alleviate timing varying channels

Patent metadata

Field	Value
Publication number	US-10985800-B2
Application number	US-202016792740-A
Country	US
Kind code	B2
Filing date	Feb 17, 2020
Priority date	Jun 19, 2018
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

Echo cancellation to alleviate timing varying channels may be provided. First, a feedback signal corresponding to one of a plurality of downstream paths and a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths may be received. Next, a plurality of echo corrected signals may be created using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other. Then a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of the plurality of echo corrected signals may be selected to use.

First claim

What is claimed is:

1. A method comprising:
receiving, by an echo cancelation component during a training window, a feedback signal corresponding to one of a plurality of downstream paths;
receiving, by the echo cancelation component during the training window, a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths;
creating, by the echo cancelation component during the training window, a plurality of echo corrected signals using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other, wherein each of the plurality of echo cancelation coefficients comprises an average of echo cancelation coefficient determined in the past over a period of time; and
selecting to use a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of the plurality of echo corrected signals.

2. The method of claim 1 , further comprising:
determining that echo cancelation performance of an output signal of the echo cancelation component has deteriorated below a predetermined threshold; and
requesting the training window in response to determining that the echo cancelation performance of the output signal of the echo cancelation component has deteriorated to the predetermined threshold.

3. The method of claim 2 , wherein determining that the echo cancelation performance of the output signal of the echo cancelation component has deteriorated below the predetermined threshold comprises determining that a Modulation Error Ratio (MER) of the output signal of the echo cancelation component has dropped below the predetermined threshold.

4. The method of claim 1 , further comprising scheduling the training window periodically.

5. The method of claim 1 , wherein the training window comprises a silence period specified in a full duplex (FDX) Data Over Cable Service Interface Specification (DOCSIS).

6. The method of claim 1 , wherein creating the plurality of echo corrected signals comprises providing the combination upstream signal to a plurality of branches wherein each of the plurality of branches respectively uses a different corresponding one of the plurality of echo cancelation coefficients.

7. The method of claim 1 , further comprising selecting the plurality of echo cancelation coefficients based on historical echo cancelation coefficient data and channel characteristics.

8. The method of claim 1 , wherein selecting to use the one of the plurality of echo cancelation coefficients that corresponds to the one of the plurality of echo corrected signals that provides the best echo cancelation performance comprises selecting to use the one of the plurality of echo cancelation coefficients that corresponds to the one of the plurality of echo corrected signals that provides the best echo cancelation performance wherein the best echo cancelation performance comprise a Modulation Error Ratio (MER).

9. The method of claim 1 , wherein receiving, by the echo cancelation component, the feedback signal comprises receiving the feedback signal wherein the echo cancelation component is disposed in a node disposed in a Hybrid Fiber-Coaxial (HFC) network.

10. A non-transitory computer-readable medium that stores a set of instructions which when executed perform a method comprising:
receiving, by an echo cancelation component during a training window, a feedback signal corresponding to one of a plurality of downstream paths;
receiving, by the echo cancelation component during the training window, a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths;
creating, by the echo cancelation component during the training window, a plurality of echo corrected signals using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other, wherein each of the plurality of echo cancelation coefficients comprises an average of echo cancelation coefficient determined in the past over a period of time; and
selecting to use a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of the plurality of echo corrected signals.

11. The computer-readable medium of claim 10 , further comprising:
determining that echo cancelation performance of an output signal of the echo cancelation component has deteriorated below a predetermined threshold; and
requesting the training window in response to determining that the echo cancelation performance of the output signal of the echo cancelation component has deteriorated to the predetermined threshold.

12. The computer-readable medium of claim 11 , wherein determining that the echo cancelation performance of the output signal of the echo cancelation component has deteriorated below the predetermined threshold comprises determining that a Modulation Error Ratio (MER) of the output signal of the echo cancelation component has dropped below the predetermined threshold.

13. The computer-readable medium of claim 10 , wherein creating the plurality of echo corrected signals comprises providing the combination upstream signal to a plurality of branches wherein each of the plurality of branches respectively uses a different corresponding one of the plurality of echo cancelation coefficients.

14. The computer-readable medium of claim 10 , further comprising selecting the plurality of echo cancelation coefficients based on historical echo cancelation coefficient data and channel characteristics.

15. The computer-readable medium of claim 10 , wherein selecting to use the one of the plurality of echo cancelation coefficients that corresponds to the one of the plurality of echo corrected signals that provides the best echo cancelation performance comprises selecting to use the one of the plurality of echo cancelation coefficients that corresponds to the one of the plurality of echo corrected signals that provides the best echo cancelation performance wherein the best echo cancelation performance comprise a Modulation Error Ratio (MER).

16. A system comprising:
a memory storage; and
a processing unit coupled to the memory storage, wherein the processing unit is operative to:
receive, during a training window, a feedback signal corresponding to one of a plurality of downstream paths;
receive, during the training window, a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths;
create, during the training window, a plurality of echo corrected signals using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other, wherein each of the plurality of echo cancelation coefficients comprises an average of echo cancelation coefficient determined in the past over a period of time; and
select to use a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of t

Assignees

• Cisco Tech Inc

Inventors

• Chapman John T
• Jin Hang
• Liu Tong

Classifications

• H04B10/25891

  Transmission components (H04B10/40 takes precedence) · CPC title

• H04B3/238 Primary

  using initial training sequence · CPC title

• H04B3/32

  Reducing cross-talk, e.g. by compensating · CPC title

• H04B3/234 Primary

  using double talk detection · CPC title