Dynamic digital communication system control

• US 7,158,563 B2
• Filed: 06/08/2001
• Issued: 01/02/2007
• Est. Priority Date: 06/01/2001
• Status: Expired due to Term

• 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: Cioffi, John M., Ginis, Georgios, Zeng, Chaohuang, Yu, Wei
• Primary Examiner(s): Corrielus; Jean B.
• Application Number:
  US09/877,724
• Publication Number:
  US 20030086514A1
• Time in Patent Office: 2,034 Days
• Field of Search: 375/224, 375/225, 375/259, 375/260, 375/285, 375/346, 370/201, 370/286, 455/295, 455/296, 455/500, 455/501, 455/59, 455/63.1, 455/67.11, 379/406.1
• US Class Current: 375/224
• 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

Methods, apparatus and systems for dynamically controlling a digital communication system, such as a DSL system, collect information about digital communication lines in the system and adaptively and/or dynamically determine line and signal characteristics of the digital communication lines, including interference effects. Based on the determined characteristics and the desired performance parameters, operation of the digital communication lines is adjusted to improve or otherwise control the performance of the system. The collection and processing of information may be performed by a party that is not a user in the system. This independent party also may control operational characteristics and parameters of the system. The invention can be used to eliminate or reduce signal interference such as crosstalk that can be induced on communication lines in systems such as DSL systems. Specific iterative power allocation and vectored transmission techniques and apparatus are disclosed.

Claims

1. A method of controlling a digital communication system having a plurality of data-carrying communication lines wherein a line'"'"'s available total power for use in the system is limited by a power constraint, the method comprising the steps of:

assigning the total power constraint for each line an initial value;

determining a competitively optimal data rate for each line by performing the steps of;

determining a power allocation within the total power constraint of each line by iteratively allowing each line to optimize its power allocation, and

determining the competitively optimal data rate for each line based on the determined power allocation for the line;

creating a model of the line, signal and the actual interference characteristics of the communication lines; and

processing signals using the model to remove interference from signals including evaluating the competitively optimal data rate for each line.

2. The method of claim 1 wherein evaluating the competitively optimal data rate for each line includes performing the steps of:

comparing the competitively optimal data rate of a line with a target rate for the line;

increasing the power constraint for a line if the competitively optimal data rate of the line is less than the target rate for the line;

decreasing the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by at least a prescribed variance;

maintaining the power constraint for the line if the competitively optimal data rate of the line is equal to the target rate for the line; and

maintaining the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by less than the prescribed variance.

3. The method of claim 1 wherein the steps of determining a competitively optimal data rate for each line and evaluating the competitively optimal data rate for each line are repeated until no power constraint is increased or decreased.

4. The method of claim 1 wherein the digital communication system is a DSL system.

5. The method of claim 1 wherein the total power allowed each line is allocated among a plurality of frequencies.

6. The method of claim 1, wherein the method is performed by a single entity.

7. The method of claim 1, wherein the method is performed by the lines in a distributed fashion.

8. The method of claim 1 wherein crosstalk interference is injected into the communication line by at least one of the other lines and wherein the crosstalk interference is considered by a line in the step of determining the power allocation of the line.

9. The method of claim 1 wherein each line uses a modem having a power limit and wherein the power constraint of a line will not be increased to a level greater than the modem power limit irrespective of the competitively optimal data rate of the line.

10. A method of controlling a digital communication system having a plurality of data-carrying communication lines wherein a line'"'"'s available total power for use in the system is limited by a power constraint, the method comprising:

assigning the total power constraint for each line an initial value;

determining a competitively optimal data rate for each line by performing the steps of;

determining a power allocation within the total power constraint of each line by iteratively allowing each line to optimize its power allocation, and

determining the competitively optimal data rate for each line based on the determined power allocation for the line;

creating a model of the line, signal and the actual interference characteristics of the communication lines; and

processing signals using the model to remove interference from signals including evaluating the competitively optimal data rate for each line, by performing the steps of;

comparing the competitively optimal data rate of a line with a target rate for the line;

increasing the power constraint for a line if the competitively optimal data rate of the line is less than the target rate for the line;

decreasing the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by at least a prescribed variance;

maintaining the power constraint for the line if the competitively optimal data rate of the line is equal to the target rate for the line; and

maintaining the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by less than the prescribed variance.

11. The method of claim 10 wherein the steps of determining a competitively optimal data rate for each line and evaluating the competitively optimal data rate for each line are repeated until no power constraint is increased or decreased.

12. The method of claim 10 wherein the digital communication system is a DSL system.

13. The method of claim 10 wherein the total power allowed each line is allocated among a plurality of frequencies.

14. The method of claim 10, wherein the method is performed by a single entity.

15. The method of claim 10, wherein the method is performed by the lines in a distributed fashion.

16. The method of claim 10 wherein crosstalk interference is injected into the communication line by at least one of the other lines and wherein the crosstalk interference is considered by a line in the step of determining the power allocation of the line.

17. The method of claim 10 wherein each line uses a modem having a power limit and wherein the power constraint of a line will not be increased to a level greater than the modem power limit irrespective of the competitively optimal data rate of the line.

18. An arrangement for controlling a digital communication system having a plurality of data-carrying communication lines, wherein a line'"'"'s available total power for use in the system is limited by a power constraint, the arrangement being adapted and programmed to perform the following steps:

assigning the total power constraint for each line an initial value;

determining a competitively optimal data rate for each line by performing the following steps;

determining a power allocation within the total power constraint of each line by iteratively allowing each line to optimize its power allocation, and

determining the competitively optimal data rate for each line based on the determined power allocation for the line;

creating a model of the line, signal and the actual interference characteristics of the communication lines; and

processing signals using the model to remove interference from signals including evaluating the competitively optimal data rate for each user, by performing the steps of;

comparing the competitively optimal data rate of a line with a target rate for the line;

increasing the power constraint for a line if the competitively optimal data rate of the line is less than the target rate for the line;

decreasing the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by at least a prescribed variance;

maintaining the power constraint for the line if the competitively optimal data rate of the line is equal to the target rate for the line; and

maintaining the power constraint for the line if the competitively optimal data rate of the line exceeds the target rate for the line by less than the prescribed variance.

19. The arrangement of claim 18 wherein the steps of determining a competitively optimal data rate for each line and evaluating the competitively optimal data rate for each line are repeated until no power constraint is increased or decreased.

20. The arrangement of claim 18 wherein the digital communication system is a DSL system.

21. The arrangement of claim 18 wherein the total power allowed each line is allocated among a plurality of frequencies.

22. The arrangement of claim 18, wherein the arrangement is performed by a single entity.

23. The arrangement of claim 18, wherein the arrangement is performed by the lines in a distributed fashion.

24. The arrangement of claim 18 wherein crosstalk interference is injected into the communication line by at least one of the other lines and wherein the crosstalk interference is considered by a line in the step of determining the power allocation of the line.

25. The arrangement of claim 18 wherein each line uses a modem having a power limit and wherein the power constraint of a line will not be increased to a level greater than the modem power limit irrespective of the competitively optimal data rate of the line.