Method and system for providing window shaping for multiline transmission in a communications system

• US 20060133519A1
• Filed: 06/06/2003
• Published: 06/22/2006
• Est. Priority Date: 06/07/2002
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Overby, Johan, Kanellakopoulos, Ioannis, Erickson, Mark A., Tsatsanis, Michail
• Granted Patent: US 7,522,515 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

A method and system for providing window shaping for multiline transmission in a communications system are described. A last portion of a prefix symbol is extracted. A prefix with a prefix window is shaped to create a shaped prefix. A DMT symbol is shaped with a DMT window to create a shaped DMT symbol. The shaped DMT symbol is combined with the shaped prefix.

Claims

1. A method, comprising:

designing a TEQ (Time EQualizer) in a DMT (Discrete Multi-Tone) system to improve throughput performance; and

reducing the number and severity of notches that the TEQ introduces in a transfer function of a shortened main channel in the DMT system.

2. The method of claim 1, wherein designing the TEQ comprises

selecting an eigenvector with a subspace-based design method;

and

computing TEQ filter coefficients with the eigenvector.

3. The method of claim 2, wherein designing the TEQ further comprises using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) method.

4. The method of claim 2, wherein designing the TEQ further comprises using a MinISI (Minimum Inter-Symbol Interference) method.

5. The method of claim 2, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

6. The method of claim 2, wherein selecting the eigenvector comprises maximizing the achievable bitrate over a subspace of eigenvectors.

7. The method of claim 6, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to a maximum eigenvalue.

8. The method of claim 1, wherein the TEQ design is used in a multiline communications system having multiple twisted copper pairs as a single multiline communications channel, and physical-layer signals coordinated across multiple transmitters and/or across multiple receivers for the purpose of minimizing interference noise from external sources, such as crosstalk noise from other high-bitrate services operating in a common binder or adjacent binders.

9. The method of claim 8, wherein designing the TEQ comprises

selecting an eigenvector with a subspace-based design method;

and

computing TEQ filter coefficients with the eigenvector.

10. The method of claim 8, wherein designing the TEQ further comprises using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) method.

11. The method of claim 8, wherein designing the TEQ further comprises using a MinISI (Minium Inter-Symbol Interference) method.

12. The method of claim 8, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

13. The method of claim 8, wherein selecting the eigenvector comprises maximizing the achievable bitrate over a subspace of eigenvectors.

14. The method of claim 13, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to a maximum eigenvalue.

15. A system, comprising:

means for designing a TEQ (Time EQualizer) in a DMT (Discrete Multi-Tone) system to improve throughput performance; and

means for reducing the number and severity of notches that the TEQ introduces in a transfer function of a shortened main channel in the DMT system.

16. The system of claim 15, wherein the means for designing the TEQ comprises

means for selecting an eigenvector with a subspace-based design system;

and

means for computing TEQ filter coefficients with the eigenvector.

17. The system of claim 16, wherein the means for designing the TEQ further comprises means for using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) system.

18. The system of claim 16, wherein means for designing the TEQ further comprises means for using a MinISI (Minimum Inter-Symbol Interference) system.

19. The system of claim 16, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

20. The system of claim 16, wherein means for selecting the eigenvector comprises means for maximizing the achievable bitrate over a subspace of eigenvectors.

21. The system of claim 20, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to a maximum eigenvalue.

22. The system of claim 15, wherein the TEQ design is used in a multiline communications system having multiple twisted copper pairs as a single multiline communications channel, and physical-layer signals coordinated across multiple transmitters and/or across multiple receivers for the purpose of minimizing interference noise from external sources, such as crosstalk noise from other high-bitrate services operating in a common binder or adjacent binders.

23. The system of claim 20, wherein means for designing the TEQ comprises

means for selecting an eigenvector with a subspace-based design system;

and

means for computing TEQ filter coefficients with the eigenvector.

24. The system of claim 22, wherein designing the TEQ further comprises means for using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) system.

25. The system of claim 22, wherein means for designing the TEQ further comprises means for using a MinISI (Minimum Inter-Symbol Interference) system.

26. The system of claim 22, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

27. The system of claim 22 wherein means for selecting the eigenvector comprises means for maximizing the achievable bitrate over a subspace of eigenvectors.

28. The system of claim 27, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to a maximum eigenvalue.

29. A computer readable medium, having stored thereon computer-readable instructions, which when executed in a computer system, cause the computer system to:

design a TEQ (Time EQualizer) in a DMT (Discrete Multi-Tone) system to improve throughput performance; and

reduce the number and severity of notches that the TEQ introduces in a transfer function of a shortened main channel in the DMT system.

30. The computer readable medium of claim 29, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to

select an eigenvector with a subspace-based design computer readable medium;

and

compute TEQ filter coefficients with the eigenvector.

31. The computer readable medium of claim 30, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to use a MSSNR (Maximum Shortening Signal-to-Noise Ratio) computer readable medium.

32. The computer readable medium of claim 30, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to use a MinISI (Minimum Inter-Symbol Interference) computer readable medium.

33. The computer readable medium of claim 30, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

34. The computer readable medium of claim 30, further having stored thereon computer-readable instructions, which when executed in the computer system to select the eigenvector, cause the computer system to maximize the achievable bitrate over a subspace of eigenvectors.

35. The computer readable medium of claim 34, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that is comparable in magnitude to a maximum eigenvalue.

36. The computer readable medium of claim 29, wherein the TEQ design is used in a multiline communications system having multiple twisted copper pairs as a single multiline communications channel, and physical-layer signals coordinated across multiple transmitters and/or across multiple receivers for the purpose of minimizing interference noise from external sources, such as crosstalk noise from other high-bitrate services operating in a common binder or adjacent binders.

37. The computer readable medium of claim 36, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to

select an eigenvector with a subspace-based design computer readable medium;

and

compute TEQ filter coefficients with the eigenvector.

38. The computer readable medium of claim 36, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to use a MSSNR (Maximum Shortening Signal-to-Noise Ratio) computer readable medium.

39. The computer readable medium of claim 36, further having stored thereon computer-readable instructions, which when executed in the computer system to design the TEQ, cause the computer system to use a MinISI (Minimum Inter-Symbol Interference) computer readable medium.

40. The computer readable medium of claim 36, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

41. The computer readable medium of claim 36, further having stored thereon computer-readable instructions, which when executed in the computer system to select the eigenvector, cause the computer system to maximize the achievable bitrate over a subspace of eigenvectors.

42. The computer readable medium of claim 41, wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to a maximum eigenvalue.

43. A method of processing a received DMT symbol that is preceded by a prefix and does not include a suffix, the method comprising:

extracting a last portion of a prefix symbol;

shaping a prefix with a prefix window to create a shaped prefix;

shaping a DMT symbol that does not include a suffix with a DMT window to create a shaped DMT symbol; and

combining the shaped DMT symbol and the shaped prefix.

44. A method of processing a received DMT symbol that has not been windowed for transmission, the method comprising:

extracting a last portion of a prefix symbol;

shaping a prefix with a prefix window to create a shaped prefix;

shaping a DMT symbol that has not been windowed for transmission with a DMT window to create a shaped DMT symbol; and

combining the shaped DMT symbol and the shaped prefix.