Dynamic digital communication system control

• US 20070081582A1
• Filed: 12/08/2006
• Published: 04/12/2007
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Ginis, Georgios, Zeng, Chaohuang, Yu, Wei, Cioffi, John
• Granted Patent: US 8,081,704 B2
• Time in Patent Office: Days
• US Class Current: 375/222
• 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 controlling a digital communication system having a plurality of communication lines on which signals are transmitted and received, the signals being affected by interference during transmission, each of the communication lines having at least one transmitter and at least one receiver, the method comprising the steps of:

for a communication line from the plurality of communication lines, creating a model of the interference characteristics due to the signals carried on the plurality of communication lines;

determining interference characteristics based on the model and actual signals carried on other communication lines from the plurality of communication lines and different from said communication line; and

compensating for actual interference on the communication line using the determined interference characteristics.

2. The method of claim 1, wherein the digital communication system is a DSL system and wherein the steps of compensating occurs at a common processing node responsive to the actual signals.

3. The method of claim 1, wherein the model is created by collecting information about a relationship between signals carried on the other communication lines and resulting interference on said communication line.

4. The method of claim 1, further including synchronizing transmission of signals between the plurality of communication lines to compensate for interference.

5. The method of claim 4, wherein the step of synchronizing transmissions of signals comprises using block transmission and reception.

6. The method of claim 1, wherein at least one of the steps of creating, determining and compensating occurs at a common processing node responsive to the actual signals and wherein the interference from the actual signals includes crosstalk from communication lines adjacent the communication line on which the signal is sent.

7. The method of claim 1, wherein at least one of the steps of creating, determining and compensating occurs at a common processing node responsive to the signals being affected over the plurality of communication lines and wherein the digital communication system uses discrete multitone transmission and the step of compensating is done on a tone by tone basis.

8. The method of claim 1, wherein at least one of the steps of creating, determining and processing occurs at a common processing node responsive to the signals being affected over the plurality of communication lines and wherein the step of processing signals using the model to remove interference from signals comprises canceling crosstalk interference in signals by QR decomposition.

9. The method of claim 1, wherein the step of creating a model is performed at a common processing node responsive to the signals being affected over the plurality of communication lines.

10. The method of claim 1, wherein each transmitter is permitted to transmit and receive signals using a data rate and wherein the step of compensating comprises analyzing a weighted sum of the data rates of the signals over the plurality of communication lines.

11. The method of claim 10, wherein the step of analyzing the weighted sum of the data rates comprises allocating energy to each of the plurality of communication lines for transmission of signals.

12. The method of claim 1, wherein the signals are sent using a plurality of frequencies and further wherein the step of compensating occurs at a common processing node responsive to the actual signals, and comprises dynamically adjusting the frequencies used to send the signals.

13. The method of claim 7, wherein the step of compensating is accomplished by modifying signals resulting from processing of the actual signals by a discrete multitone receiver.

14. The method of claim 7, wherein the step of compensating is accomplished by modifying signals that are used by a discrete multitone transmitter to transmit the actual signals.

15. A method of controlling a digital communication system having a plurality of communication lines on which signals are transmitted and received, the signals being affected by interference during transmission, each of the communication lines having at least one transmitter and at least one receiver, the method comprising:

compensating for interference on a communication line from the plurality of communication lines using a model responsive to actual signals carried on each of the plurality of communication lines.

16. The method of claim 15, wherein the digital communication system is a DSL system and wherein the step of compensating occurs at a common processing node responsive to the signals being affected over the plurality of communication lines.

17. The method of claim 15, wherein the step of compensating includes modifying a signal responsive to the actual signals being carried over the plurality of communication lines.

18. The method of claim 17, further including the step of synchronizing transmission of signals between the plurality of communication lines.

19. The method of claim 18, further including the step of synchronizing transmissions of signals using block transmission and reception.

20. The method of claim 15, wherein the step of compensating occurs at a common processing node responsive to the signals being affected over the plurality of communication lines and wherein the interference on a communication line includes crosstalk from adjacent ones of the plurality of communication lines.

21. The method of claim 15, wherein the step of compensating is done on a tone by tone basis and occurs at a common processing node responsive to the actual signals and wherein the digital communication system uses discrete multitone transmission.

22. The method of claim 15, wherein the step of compensating occurs at a common processing node responsive to the signals being affected over the plurality of communication lines and comprises canceling crosstalk interference between signals by matrix decomposition.

23. The method of claim 15, further including the step of collecting information about line, signal and interference characteristics of the communication lines at a common processing node responsive to the signals, wherein the information is used to generate the model.

24. The method of claim 15, wherein each user of a communication line is permitted to transmit and receive signals using a data rate and wherein the step of compensating comprises analyzing a weighted sum of the data rates of the signals over the plurality of communication lines.

25. The method of claim 24, wherein the step of analyzing the weighted sum of the data rates comprises allocating energy to each of the plurality of communication lines for transmission of signals.

26. The method of claim 15, wherein the signals are sent using a plurality of frequencies and further wherein the step compensating occurs at a common processing node responsive to the signals being affected over the plurality of communication lines, and comprises dynamically adjusting the frequencies used to send the signals.

27. The method of claim 15, wherein the actual signals represent input signals from users, the actual signals are separated into a plurality of tones and each tone has interference cancellation performed relative to the actual signals and the model.

28. The method of claim 27, wherein the interference cancellation occurs before a discrete multitone transmitter transmits the actual symbols over the plurality of communication lines.

29. The method of claim 27, wherein the interference cancellation occurs after a discrete multitone receiver receives the actual symbols over the plurality of communication lines.

30. An arrangement for controlling communication in a digital communication system having a plurality of communication lines on which signals are transmitted and received, the signals being affected by interference during transmission, the arrangement comprising:

a first processing arrangement that creates a model of the interference characteristics of a communication line selected from the plurality of communication lines, the interference characteristics due to signals carried on the plurality of communication lines; and

a second processing arrangement that processes signals using the model to determine interference characteristics created by actual signals carried on the other communication lines, and in response, remove interference from the actual signals.

31. The arrangement of claim 30, wherein the digital communication system is a DSL system and wherein the second processing arrangement processes signals at a common processing node responsive to the actual signals.

32. The arrangement of claim 30, wherein the second processing arrangement further uses the model for modifying a signal responsive to the signals being affected over the plurality of communication lines.

33. The arrangement of claim 30, wherein the second processing arrangement further uses the model for synchronizing transmission of signals between the plurality of communication lines.

34. The arrangement of claim 33, further including at least one block that synchronizes transmissions of signals using block transmission and reception.

35. The arrangement of claim 30, wherein the second processing arrangement processes signals at a common processing node responsive to the actual signals and wherein the interference from the actual signals includes crosstalk from adjacent ones of the communication lines.

36. The arrangement of claim 30, wherein the second processing processes signals at a common processing node responsive to the signals being affected over the plurality of communication lines and wherein the digital communication system uses discrete multitone transmission and using the model to remove interference from the actual signals is performed on a tone by tone basis.

37. The arrangement of claim 30, wherein the second processing arrangement processes signals at a common processing node responsive to the actual signals being affected over the plurality of communication lines and wherein the second processing arrangement further uses the model for canceling crosstalk interference in signals by matrix decomposition.

38. The arrangement of claim 30, further including a plurality of user blocks, wherein at least one block operates independent from other blocks and adapted to collect information about line, signal and interference characteristics of the communication lines at a common processing node responsive to the actual signals.

39. The arrangement of claim 38, wherein each user block is permitted to transmit and receive signals using a data rate and wherein the second processing arrangement is further adapted to analyze a weighted sum of the data rates of the signals over the plurality of communication lines.

40. The arrangement of claim 39, wherein the second processing arrangement further allocates energy to each of the plurality of communication lines for transmission of signals.

41. The arrangement of claim 40 wherein the signals are sent using a plurality of frequencies and further wherein the second processing arrangement is further adapted to dynamically adjust the frequencies used to send the signals.

42. An arrangement for controlling communication in a digital communication system having a plurality of communication lines on which signals are transmitted and received, the signals being affected by interference during transmission, the arrangement comprising:

processing means for creating a model of the interference on a communication line from the plurality of communication lines due to other communication lines of the plurality of communication lines; and

processing means for processing signals using the model to determine the interference characteristics created by actual signals carried on the other communication lines, and in response, remove the interference from the actual signals.