Dynamic digital communication system control

• US 8,681,897 B2
• Filed: 06/19/2012
• Issued: 03/25/2014
• Est. Priority Date: 06/01/2001
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Ginis, Georgios, Yu, Wei, Zeng, Chaohuang, Cioffi, John M.
• Primary Examiner(s): Corrielus, Jean B
• Application Number:
  US13/527,074
• Publication Number:
  US 20120257691A1
• Time in Patent Office: 644 Days
• Field of Search: 375/224, 375/227, 375259-260, 375/285, 375295-296, 375/316, 375/340, 375/346, 375348-350, 370/201, 379/414, 379416-417, 379/392.01, 455/295, 455/296, 455/501, 455/63.1
• US Class Current: 375/296
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/1081 Reduction of multipath noise by equalising H04B7/005
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 2001/1045 Adjacent-channel interference
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04B 3/46 Monitoring; Testing
• CPC Class Codes: H04B 3/466 Testing attenuation in combination with at least one of group delay and phase shift
• CPC Class Codes: H04B 3/487 Testing crosstalk effects
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 7/0016 correction of synchronization errors
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

Control of a digital communication system having a plurality of communication lines on which signals are transmitted and received is implemented using a variety of methods and systems. According to one embodiment of the present invention, a method is implemented where the signals are affected by interference during transmission and each of the communication lines has at least one transmitter and at least one receiver. A model is created of the interference characteristics due to the signals carried on the communication lines. Interference characteristics for a line are determined based on the model and actual signals carried on other communication lines different from the line for which the characteristics are being determined. Actual interference is compensated for on the communication line using the determined interference characteristics.

Claims

1. A method of vectored transmission in a Digital Subscriber Line (DSL) system using Discrete Multi-tone communications over a plurality of communications lines, each of the plurality of communication lines having at least one transmitter and at least one receiver, and wherein cross-talk interference between the plurality of communication lines occurs during transmission, the method comprising:

providing signals within a plurality of tones to a precoder block,

determining parameters of the precoder block using a communication adaptation unit and line and signal characteristics of the plurality of communication lines,

pre-distorting the signals within the plurality of tones using the precoder block and the determined parameters, wherein pre-distorting is performed on a tone separately from pre-distorting on other tones, and

transmitting the pre-distorted signals on at least one of the plurality of communication lines, wherein the cross-talk interference is eliminated or reduced by transmission of the pre-distorted signals on the at least one of the plurality of communications lines.

2. The method of claim 1, further including the step of performing block transmission using the DSL system.

3. The method of claim 2, further including the step of performing block reception and wherein the block transmission and reception are synchronized.

4. The method of claim 1, wherein determining the parameters of the precoder block relies on knowledge of at least one of a channel matrix and a noise covariance matrix.

5. The method of claim 4, further including the step of obtaining the channel matrix knowledge by training-based channel identification performed during initialization.

6. The method of claim 1, wherein the transmission is at least one of an upstream communication, and downstream communication.

7. A method of DSL communication at a device transmitting from the device in one direction according to claim 1, the method for reception at the device in another direction, further comprising:

receiving other signals within the plurality of tones from at least one of the plurality of communication lines,

determining parameters of a canceller block using the communication adaptation unit and line and signal characteristics of the plurality of communication lines,

eliminating or reducing, using the canceller block and the determined parameters, crosstalk within each tone of the plurality of tones of the other signals received from at least one of the plurality of communication lines, and

receiving the other signals within each tone from the canceller block.

8. The method of claim 7, further including employing block transmission using the DSL system.

9. The method of claim 8, further including employing block reception using the DSL system, and wherein the block transmission and reception are synchronized.

10. The method of claim 7, wherein determining the parameters of the canceller block relies on knowledge of at least one of a channel matrix and a noise covariance matrix.

11. The method of claim 10, further including the step of obtaining the channel matrix knowledge by training-based channel identification performed during initialization.

12. The method of claim 7, wherein the transmission is at least one of an upstream communication, and downstream communication.

13. A Digital Subscriber Line (DSL) system for vectored transmission comprising:

a plurality of transmitters configured and arranged to use Discrete Multi-tone communications over a plurality of communications lines, wherein cross-talk interference between the communication lines occurs during transmission;

a precoder block configured and arranged to receive signals within a plurality of tones and to pre-distort the signals within a tone independently of other tones in response to a plurality of parameters, and to provide the pre-distorted signals to at least one of the plurality of transmitters for transmission on at least one of the plurality of communication lines, and

a communication adaption unit configured and arranged to determine, based upon line and signal characteristics of the plurality of communication lines, the plurality of parameters of the precoder block, wherein the crosstalk interference is eliminated or reduced from the pre-distorted signals as transmitted on at least one of the plurality of communications lines.

14. The system of claim 13, wherein the plurality of transmitters are further configured and arranged to perform block transmission.

15. The system of claim 14, wherein the plurality of transmitters are further configured and arranged to synchronize the block transmission.

16. The system of claim 13, wherein the communication adaption unit is further configured and arranged to determine the parameters of the precoder block based upon knowledge of at least one of a channel matrix and a noise covariance matrix.

17. The system of claim 16, wherein the communication adaption unit is further configured and arranged to obtain the channel matrix knowledge by training-based channel identification performed during initialization.

18. A Digital Subscriber Line (DSL) system for vectored transmission, the transmission in one direction according to claim 13, the system further comprising

a plurality of receivers configured and arranged for Discrete Multi-tone reception of other signals in another direction within the plurality of tones from the plurality of communications lines, wherein cross-talk interference occurs between the plurality of communications lines,

a canceller block configured and arranged to eliminate or reduce crosstalk within each tone of the plurality of tones of the other signals received from the at least one of the communication lines, using the canceller block and parameters, and to provide signals within each tone, and

the communication adaptation unit configured and arranged to determine the parameters of the canceller block using line and signal characteristics of the plurality of communication lines.

19. The system of claim 18, wherein the communication adaption unit is further configured and arranged to determine the parameters of the canceller block based upon knowledge of at least one of a channel matrix and a noise covariance matrix.

20. The system of claim 19, wherein the communication adaption unit is further configured and arranged to obtain the channel matrix knowledge by training-based channel identification performed during initialization.

21. The system of claim 18, wherein the plurality of receivers are configured and arranged for at least one of upstream communication and downstream communication.