Method for distributed spectrum management of digital communications systems

• US 7,813,293 B2
• Filed: 05/12/2006
• Issued: 10/12/2010
• Est. Priority Date: 05/12/2006
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Inventors: Evans, Jamie Scott, Papandriopoulos, John
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Mui; Gary
• Application Number:
  US11/433,025
• Publication Number:
  US 20070274404A1
• Time in Patent Office: 1,614 Days
• Field of Search: 370/201, 370/252, 370/253, 370/468, 375/252, 375/254, 375/130, 375240-241, 703 18- 22, 703/2
• US Class Current: 370/252
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 5/0044 allocation of payload

Abstract

A method for distributed spectrum management of digital communication systems having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of: collecting information about line, signal and interference characteristics of a plurality of the communication lines from a plurality of sources; determining the line, signal and interference characteristics of a plurality of the communication lines; varying power allocation of particular plurality of the communication lines between respective transmitter and receiver taking into consideration the determined line, signal and interference characteristics of a plurality of the communication lines and consideration of a noise weight of a plurality of the communication lines to enable a minimum power on a plurality of the communication lines and to allow required effective data-rates for each of said respective users to be satisfied.

Claims

1. A method for distributed spectrum management of a digital communication system having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of:

a. collecting information about line, signal and interference characteristics of a specific plurality of the communication lines from a plurality of sources;

b. determining the line, signal and interference characteristics of said specific plurality of the communication lines; and

c. varying power allocation of said specific plurality of the communication lines between respective transmitters and receivers using (i) the determined line, signal and interference characteristics of said specific plurality of the communication lines and (ii) respective noise weights of said specific plurality of the communication lines.

2. The method of claim 1, comprising providing required effective data-rates for each fixed margin user, wherein the required effective data-rates allow target data-rates for each of said respective users to be satisfied with minimum power.

3. The method of claim 1, comprising maximizing data-rates with minimum power rate adaptive users to be satisfied with minimum power.

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

5. The method of claim 1 wherein the step of determining the line, signal and interference characteristics of said specific plurality of the communication lines includes creating a model of the communication lines and determining crosstalk gains of said specific plurality of the communication lines from said model.

6. The method of claim 1 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources is coordinated by a spectrum management centre.

7. The method of claim 1 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a plurality of signal to interference ratio (SIR) of said communication lines and collating noise weight

8. The method of claim 7 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources includes combining consideration of respective user requirements to calculate and provide a weighted noise for each line to be used in the step of varying power allocation of particular communication lines between respective transmitter and receiver.

9. The method of claim 8 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a QoS parameter combining collected line measurements and respective user requirements.

10. The method of claim 9 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining the QoS parameter δ

_k by

11. The method of claim 8 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a QoS parameter δ

_k=ω

_k, wherein there is a maximization of users data rate according to their respective weighting.

12. The method of claim 1 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver uses a combined noise determined from two or more of:

said noise weights;

crosstalk line characteristics;

signal and interference characteristics; and

a parameter over a particular communication line.

13. The method of claim 12 wherein the step of aggregating noise weights and crosstalk line characteristics over said specific plurality of communication lines to form a combined noise is undertaken at a SMC.

14. The method of claim 12 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver involves determining a maximum power penalty for each user taking other users into account and altering the power allocation of particular communication lines to a level within a power budget.

15. The method of claim 14 wherein the step of determining a maximum power penalty for each communication line is undertaken locally by each user using only local information including a received combined noise.

16. The method of claim 14 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver involves determining a target rate penalty for each user and altering the power allocation of particular communication lines according to said respective target rate penalty to thereby meet the required target data rate.

17. The method of claim 16 wherein the step of determining a target rate penalty for each communication line is undertaken locally by each user using only local information.

18. The method of claim 16 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver involves obtaining a target rate penalty by convergence of two determinations for each user.

19. The method of claim 18 using bisection calculation.

20. The method of claim 18 using (sub)gradient-based update calculation.

21. The method of claim 18 using ellipsoid method calculation.

22. The method of claim 12 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver uses the calculation of combined noise, performed on a tone-by-tone basis, according to the following formula

23. The method of claim 1 wherein the step of collecting information about line, signal and interference characteristics of the communication lines from a plurality of sources comprises using network loop characteristics.

24. The method of claim 1 wherein the interference affecting transmission of signals includes crosstalk from communication lines in one or more of the categories of NEXT and FEXT interference.

25. The method of claim 1 wherein the step of varying the power is modified by a preselected weighting system in said communication lines or modified by a preselected target data rate according to selected QoS for each communication line.

26. The method of claim 1 wherein the step of collecting information about line, signal and interference characteristics of the communication lines is performed by a plurality of transmitters and receivers of networked communication lines of a plurality users.

27. The method of claim 1 wherein each user is permitted to transmit and receive signals within an allowable power range and wherein the step of varying power allocation of particular plurality of the communication lines between respective transmitter and receiver uses a model to determine respective power allocation of each communication line based on determined line characteristics, noise weights, and selected QoS for each communication line.

28. The method of claim 27 wherein the step of varying power allocation of each line determines acceptable minimal power allocation for each line.

29. The method of claim 14 wherein the step of varying power allocation of particular plurality of the communication lines between respective transmitter and receiver the power of signals is adjusted for each tone based on the requirements of the localized SIR and on the effect of power allocation on other users by determining allocated power as

30. The method of claim 12, comprising obtaining comprising obtaining crosstalk gains G_jkⁿ of said crosstalk line characteristics from a measurement process.

31. The method of claim 12, comprising obtaining crosstalk gains G_jkⁿ of said crosstalk line characteristics using crosstalk models and loop topology information.

32. The method of claim 12 wherein the determination of power allocation of particular plurality of the communication lines occurs at the SMC.

33. The method of claim 32 wherein the power allocation determination is translated into one or more spectral masks that are consequently sent to a particular plurality of the communication lines and where the step of varying power allocation of said communication lines is then locally determined, where the power is locally controlled by the particular plurality of the communication lines to be the required level if less than the level indicated by the said spectral mask or is the allocated maximum power level indicated by the said spectral mask.

37. The method of claim 1, including minimizing power on said specific plurality of the communication lines and providing required effective data-rates for each of said respective users.

47. The method of claim 14 wherein the step of varying power allocation of particular communication lines between respective transmitter and receiver involves obtaining an optimum maximum power penalty by convergence of two determinations for each user.

34. A digital communication system having distributed spectrum management of a plurality of communication lines extending between respective receivers and transmitters, the system comprising:

a. a noise weight calculator for determining a weighted noise of each of a plurality of communication lines;

b. a weighted noise aggregator for aggregating the weighted noises of each of the respective plurality of communication lines and outputting combined noise for each communication lines;

c. a power allocation determinator for determining allocated power of a communication line based on the combined noises of the plurality of communication lines of the digital communication systems; and

d. bit loading mapper for determining appropriate bit-loading for use in transmission on the communication lines.

35. A digital communication system according to claim 34 wherein each communication line has power allocation determinator for receiving said combined noise and able to locally determine allocated power of its respective communication line based on the determined power needs of the plurality of communication lines of the digital communication systems.

36. A digital communication system according to claim 35 wherein the weighted noise aggregator is located at a SMC.

38. A method for distributed spectrum management of digital communication systems having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of:

a. collecting information about line, signal and interference characteristics of a specific plurality of the communication lines from a plurality of sources;

b. determining the line, signal and interference characteristics of said specific plurality of the communication lines; and

c. varying power allocation of said specific plurality of the communication lines between respective transmitters and receivers using (i) the determined line, signal and interference characteristics of said specific plurality of the communication lines and;

(ii) respective noise weights of said specific plurality of the communication lines to enable a minimum power on a plurality of the communication lines and to allow required effective data-rates for each of said respective users to be satisfied;

wherein said collecting of information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a plurality of signal to interference ratio (SIR) of said communication lines and collating noise weight

39. The method of claim 38 wherein said collecting of information about line, signal and interference characteristics of the communication lines from a plurality of sources includes combining consideration of respective user requirements to calculate and provide a weighted noise for each line to be used in the step of varying power allocation of particular communication lines between respective transmitter and receiver.

40. The method of claim 39 wherein said collecting of information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a QoS parameter combining collected line measurements and respective user requirements.

41. The method of claim 40 wherein said collecting of information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining the QoS parameter δ

_k by

42. The method of claim 39 wherein said collecting of information about line, signal and interference characteristics of the communication lines from a plurality of sources includes determining a QoS parameter δ

_k=ω

_k, wherein there is a maximization of users data rate according to their respective weighting.

43. A method for distributed spectrum management of digital communication systems having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of:

a. collecting information about line, signal and interference characteristics of a specific plurality of the communication lines from a plurality of sources;

b. determining the line, signal and interference characteristics of said specific plurality of the communication lines;

c. varying power allocation of said specific plurality of the communication lines between respective transmitters and receivers using (i) the determined line, signal and interference characteristics of said specific plurality of the communication lines, (ii) respective noise weights of said specific plurality of the communication lines, and (iii) a combined noise determined from an aggregate of said noise weights and crosstalk line characteristics over said specific plurality of the communication lines; and

d. determining crosstalk gains of said crosstalk line characteristics from a measurement process.

44. The method of claim 43, including minimizing power on said specific plurality of the communication lines and providing required effective data-rates for each of said respective users.

45. A method for distributed spectrum management of digital communication systems having a plurality of communication lines on which signals are transmitted and received by respective users, the method comprising the steps of:

a. collecting information about line, signal and interference characteristics of a specific plurality of the communication lines from a plurality of sources;

b. determining the line, signal and interference characteristics of said specific plurality of the communication lines;

c. varying power allocation of said specific plurality of the communication lines between respective transmitters and receivers using (i) the determined line, signal and interference characteristics of said specific plurality of the communication lines, (ii) respective noise weights of said specific plurality of the communication lines, and (iii) a combined noise determined from an aggregate of said noise weights and crosstalk line characteristics over said specific plurality of the communication lines; and

d. obtaining crosstalk gains of said crosstalk line characteristics using crosstalk models and loop topology information.

46. The method of claim 45, including minimizing power on said specific plurality of the communication lines and providing required effective data-rates for each of said respective users.