Method and apparatus for determination of vectoring matrices

Patent metadata

Field	Value
Publication number	US-11115080-B2
Application number	US-201716077850-A
Country	US
Kind code	B2
Filing date	Feb 23, 2017
Priority date	Feb 26, 2016
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A vectoring controller is configured to determine first coefficient values for a vectoring matrix at a first tone based on a first number of iterations through an iterative update algorithm and a first channel matrix estimate at the first tone, and to determine second coefficient values for the vectoring matrix at a second neighboring tone based on a second number of iterations through the iterative update algorithm and a second channel matrix estimate at the second tone. The vectoring controller is configured to start with the first coefficient values as initial values for the respective second coefficient values in the iterative update algorithm. The second number of iterations is lower than or equal to the first number of iterations.

First claim

The invention claimed is:

1. A vectoring controller configured to determine a vectoring matrix that is used for joint processing of Discrete Multi-Tone DMT communication signals to be transmitted over, or received from, a plurality of subscriber lines, the vectoring controller being configured to determine first coefficient values for the vectoring matrix at a first tone based on a first number of iterations through an iterative update algorithm and based on a first channel matrix estimate at the first tone, and to determine second coefficient values for the vectoring matrix at a second neighboring tone based on a second number of iterations through the iterative update algorithm and based on a second channel matrix estimate at the second tone,
wherein the vectoring controller is further configured to start with default coefficient values as initial values for the determination of the first coefficient values through the iterative update algorithm, and to start with the first coefficient values as initial values for the determination of the second coefficient values through the iterative update algorithm,
and wherein the vectoring controller is further configured to set the second number of iterations to a value that is lower than the first number of iterations.

2. A vectoring controller according to claim 1 , wherein the iterative algorithm is an iterative Minimum Mean Squared Error iMMSE update algorithm, and wherein the vectoring controller is further configured to set the second number of iterations to 1.

3. A vectoring controller according to claim 1 , wherein the iterative algorithm is a Schulz update algorithm,
and wherein the vectoring controller is further configured to set the second number of iterations to 1, 2 or 3.

4. A vectoring controller according to claim 1 , wherein the vectoring controller is further configured to derive the first and second channel matrix estimates from raw Discrete Fourier Transform DFT samples of signals received from the subscriber lines while crosstalk probing signals are being transmitted over the subscriber lines.

5. A vectoring controller according to claim 1 , wherein the vectoring controller is further configured to derive the first and second channel matrix estimates from slicer error samples of signals received from the subscriber lines while crosstalk probing signals are being transmitted over the subscriber lines.

6. A vectoring controller according to claim 1 , wherein the vectoring controller is further configured to determine third coefficient values for the vectoring matrix at a third further-neighboring tone based on a third number of iterations through the iterative update algorithm and based on a third channel matrix estimate at the third tone,
wherein the vectoring controller is further configured to start with the second coefficient values as initial values for the determination of the respective third coefficient values through the iterative update algorithm,
and wherein the vectoring controller is further configured to set the third number of iterations to a value that is lower than to the first number of iterations.

7. A vectoring controller according to claim 6 , wherein the first, second and third tones are tones with increasing or decreasing tone index.

8. A vectoring controller according to claim 7 , wherein the first tone is selected from among a set of reference tones.

9. A vectoring controller according to claim 1 , wherein the vectoring controller comprises a processor, a fast-access memory and a slower-access memory,
wherein the slower-access memory is configured to hold the first channel matrix estimate, wherein the fast-access memory is configured to load the first channel matrix estimate from the slower-access memory,
wherein the processor is configured to read the first channel matrix estimate from the fast-access memory, to determine the first coefficient values, and to write the first coefficient values into the fast-access memory,
wherein the slower-access memory is configured to load the first coefficient values from the fast-access memory, and to hold the first coefficient values for further configuration of a vectoring processor,
and wherein the first coefficient values are retained in the fast-access memory for further determination of the second coefficient values.

10. A vectoring controller according to claim 9 , wherein the processor is further configured to determine the second coefficient values, and to substitute the second coefficient values for the first coefficient values in the fast-access memory,
and wherein the second coefficient values are retained in the fast-access memory for further determination of the third coefficient values.

11. A vectoring controller according to claim 9 , wherein the processor is configured to run multiple threads for determination of coefficient values for the vectoring matrix at respective tones.

12. An access node comprising a vectoring controller according to claim 1 .

13. A method for determining a vectoring matrix that is used for joint processing of Discrete Multi-Tone DMT communication signals to be transmitted over, or received from, a plurality of subscriber lines, the method comprising:
determining first coefficient values for the vectoring matrix at a first tone based on a first number of iterations through an iterative update algorithm and based on a first channel matrix estimate at the first tone;
determining second coefficient values for the vectoring matrix at a second neighboring tone based on a second number of iterations through the iterative update algorithm and based on a second channel matrix estimate at the second tone;
wherein the method further comprises starting with default coefficient values as initial values for the determining the first coefficient values through the iterative update algorithm, and starting with the first coefficient values as initial values for the determining the second coefficient values through the iterative update algorithm,
and wherein the second number of iterations is set to a value that is lower than the first number of iterations.

Assignees

• Alcatel Lucent

Inventors

• Bastos Moraes Rodrigo
• Tsiaflakis Paschalis
• Jivanescu Mihaela
• Maes Jochen
• Nuzman Carl

Classifications

• H04M3/34

  Testing for cross-talk · CPC title

• H04B3/32 Primary

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

• H04M3/30

  for subscriber's lines {, for the local loop} · CPC title