Crosstalk channel estimation for legacy CPE

Patent metadata

Field	Value
Publication number	US-10505583-B2
Application number	US-201715410131-A
Country	US
Kind code	B2
Filing date	Jan 19, 2017
Priority date	Dec 19, 2016
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A digital subscriber line (DSL) network device for coupling to DSL communication lines, the network device comprising: multiplexing circuitry that transmits signals to vector-compliant consumer premises equipment (CPE) and legacy CPE via the DSL communication lines; and processing circuitry configured to: initiate transmission of a predetermined set of orthogonal pilot sequences to a plurality of vector-compliant CPEs; initiate transmission of data symbols corresponding to the set of orthogonal pilot sequences to one or more legacy CPEs; pre-process line errors of a victim vector-compliant CPE to remove far-end crosstalk due to the vector compliant disturber lines and perform the same pre-processing for the transmitted data symbols; determine far-end channel crosstalk information using a correlation of the pre-processed line errors and the pre-processed transmitted data symbols; and reduce far-end channel crosstalk of the victim vector-compliant CPE using the determined far-end channel crosstalk information.

First claim

What is claimed is:

1. A digital subscriber line (DSL) network device for coupling to DSL communication lines, the DSL network device comprising:
multiplexing circuitry configured to transmit signals to vector-compliant consumer premises equipment (CPE) and legacy CPE via the DSL communication lines; and
processing circuitry configured to:
initiate transmission of a predetermined set of orthogonal pilot sequences to one or more disturber vector-compliant CPEs;
initiate transmission of data symbols corresponding to the predetermined set of orthogonal pilot sequences to one or more disturber legacy CPEs;
pre-process line errors of a victim vector-compliant CPE, due to the transmitting of the predetermined set of orthogonal pilot sequences, to remove far-end crosstalk due to the vector compliant disturber lines and perform the same pre-processing for the transmitted data symbols;
determine far-end channel crosstalk information between network device ports connected to the one or more disturber legacy CPEs and a network device port connected to the victim vector-compliant CPE using a correlation of the pre-processed line errors and the pre-processed transmitted data symbols; and
pre-code subsequent signals transmitted by the DSL network device via the vectored lines with a compensation factor, the compensation factor determined using the far-end channel crosstalk information, and applied to reduce far-end channel crosstalk of the victim vector-compliant CPE.

2. The DSL network device of claim 1 , wherein the processing circuitry is configured to pre-code the subsequent signals to transmit via the one or more disturber vector-compliant CPEs using an inverse of an estimated far-end channel crosstalk signal.

3. The DSL network device of claim 1 , wherein the processing circuitry is configured to transmit a pilot sequence of all ones to all vector-compliant CPEs and transmitting data symbols corresponding to the pilot sequence of all ones to all legacy CPEs, and pre-process the line errors by determining a difference between every two adjacent synchronization (SYNC) symbol errors and every two adjacent data symbols for a channel of the victim vector-compliant CPE.

4. The DSL network device of claim 1 , wherein the processing circuitry is configured to transmit a pilot sequence of alternating ones and zeros to all vector-compliant CPEs and transmit data symbols corresponding to the pilot sequence of alternating ones and zeros to all legacy CPEs, and pre-process the line errors by determining a sum between every two adjacent SYNC symbol errors and every two adjacent data symbols for a channel of the victim vector-compliant CPE.

5. The DSL network device of claim 1 , wherein the processing circuitry is configured to transmit a specified pilot sequence twice in succession to the disturber vector-compliant CPEs and transmit data symbols corresponding to the specified pilot sequence twice in succession to the disturber legacy CPEs, and pre-process the line errors by determining a difference between every two SYNC symbol errors corresponding to the two instances of the pilot sequence and data symbols corresponding to the two instances of the pilot sequence for a channel of the victim vector-compliant CPE.

6. The DSL network device of claim 1 , wherein the processing circuitry is configured to transmit each bit of a specified pilot sequence twice in succession to the disturber vector-compliant CPEs and transmit data symbols corresponding to each bit of the specified pilot sequence twice in succession to the disturber legacy CPEs, and pre-process the line errors by determining a difference between every two adjacent SYNC symbol errors corresponding to a same pilot sequence bit and every two adjacent data symbols corresponding to the same pilot sequence bit for a channel of the victim vector-compliant CPE.

7. The DSL network device of claim 1 , wherein the line errors include decoding errors of the victim vector-compliant CPE.

8. The DSL network device of claim 1 , wherein the line errors include Fast Fourier transform (FFT) outputs of the victim vector-compliant CPE.

9. A computer-implemented method of assessing far-end channel crosstalk in digital subscriber line (DSL) communications, the method comprising:
transmitting a predetermined set of orthogonal pilot sequences from a DSL network device to one or more disturber vector-compliant consumer premises equipment (CPE);
transmitting data symbols corresponding to the predetermined set of orthogonal pilot sequences from the DSL network device to one or more disturber legacy CPEs;
pre-processing, at the DSL network device, line errors of a victim vector-compliant CPE due to the transmitting of the predetermined set of orthogonal pilot sequences to remove far-end crosstalk due to the vector compliant disturber lines and performing the same pre-processing for the transmitted data symbols;
determining far-end channel crosstalk information between network device ports connected to the one or more disturber legacy CPEs and network device ports connected to the victim vector-compliant CPE using a correlation of the pre-processed line errors and the pre-processed transmitted data symbols; and
reducing far-end channel crosstalk of the victim vector-compliant CPE, by pre-coding subsequent signals transmitted by the DSL network device via the vectored lines with a compensation factor determined using the determined far-end channel crosstalk information.

10. The method of claim 9 , wherein the reducing far-end channel crosstalk of the victim vector-compliant CPE includes pre-coding the subsequent signals for transmitting via the one or more first vector-compliant CPEs using an inverse of the determined far-end channel crosstalk information.

11. The method of claim 9 , wherein transmitting a predetermined set of orthogonal pilot sequences includes transmitting a pilot sequence of all ones to all vector-compliant CPEs and transmitting data symbols corresponding to the pilot sequence of all ones to all legacy CPEs, and wherein the pre-processing the line errors includes determining a difference between every two adjacent synchronization (SYNC) symbol errors and every two adjacent data symbols for a channel of the victim vector-compliant CPE.

12. The method of claim 9 , wherein transmitting a predetermined set of orthogonal pilot sequences includes transmitting a pilot sequence of alternating ones and zeros to all vector-compliant CPEs and transmitting data symbols corresponding to the pilot sequence of alternating ones and zeros to all legacy CPEs, and wherein pre-processing line errors includes determining a sum between every two adjacent SYNC symbol errors and every two adjacent data symbols for a channel of the vector-compliant CPE.

13. The method of claim 9 , wherein transmitting a predetermined set of orthogonal pilot sequences includes transmitting a specified pilot sequence twice in succession to the disturber vector-compliant CPEs and transmitting data symbols corresponding to the specified pilot sequence twice in succession to the disturber legacy CPEs, and wherein pre-processing line errors includes determining a difference between SYNC symbol errors corresponding to the two instances of the pilot sequence and data symbols corresponding to the two instances of the pilot sequence for a channel of the vector-compliant CPE.

14. The method of claim 9 , wherein transmitting a predetermined set of orthogonal pilot sequences includes transmitting each bit of a specified pilot sequence twice in succession and transmitting data symbols corresponding to each bit of the specified pilot sequence twice in succession to all lega

Assignees

• Futurewei Technologies Inc

Inventors

• Liang Haixiang
• He Yujie
• Tu Jianping

Classifications

• H04B3/32 Primary

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

• H04L25/03343

  Arrangements at the transmitter end · CPC title

• H04L27/2626

  Arrangements specific to the transmitter only · CPC title