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

• US 7,522,515 B2
• Filed: 06/06/2003
• Issued: 04/21/2009
• Est. Priority Date: 06/07/2002
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Tsatsanis, Michail, Overby, Johan, Kanellakopoulos, Ioannis, Erickson, Mark A.
• Primary Examiner(s): Pham; Brenda
• Assistant Examiner(s): CHAN, SAI MING
• Application Number:
  US10/517,095
• Publication Number:
  US 20060133519A1
• Time in Patent Office: 2,146 Days
• Field of Search: 370/260, 370/210, 370/529, 370525-527, 375/222, 375/348
• US Class Current: 370/210
• 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 by;

selecting in the DMT system an eigenvector with a subspace-based design method; and

computing in the DMT system TEQ filter coefficients with the eigenvector; and

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

wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue,

wherein selecting the eigenvector comprises maximizing an achievable bitrate over a subspace of eigenvectors, and

wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to the maximum eigenvalue.

2. The method of claim 1, wherein designing the TEQ further comprises using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) method.

3. The method of claim 1, wherein designing the TEQ further comprises using a MinISI (Minimum Inter-Symbol Interference) method.

4. 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.

5. The method of claim 4, wherein designing the TEQ further comprises using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) method.

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

7. The method of claim 4, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

8. The method of claim 4, wherein selecting the eigenvector comprises maximizing the achievable bitrate over a sub space of eigenvectors.

9. The method of claim 8, 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.

10. A system, comprising:

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

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

means for computing TEQ filter coefficients with the eigenvector; 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,

wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue,

wherein means for selecting the eigenvector comprises means for maximizing an achievable bitrate over a subspace of eigenvectors, and

wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that are comparable in magnitude to the maximum eigenvalue.

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

12. The system of claim 10, wherein means for designing the TEQ further comprises means for using a MinISI (Minimum Inter-Symbol Interference) system.

13. The system of claim 10, 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.

14. The system of claim 13, wherein designing the TEQ further comprises means for using a MSSNR (Maximum Shortening Signal-to-Noise Ratio) system.

15. The system of claim 13, wherein means for designing the TEQ further comprises means for using a MinISI (Minimum Inter-Symbol Interference) system.

16. The system of claim 13, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

17. The system of claim 13, wherein means for selecting the eigenvector comprises means for maximizing the achievable bitrate over a sub space of eigenvectors.

18. The system of claim 17, 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.

19. A computer readable medium, having stored thereon computerreadable 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 by;

selecting an eigenvector with a subspace-based design computer readable medium by maximizing an achievable bitrate over a subspace of eigenvectors; and

computing TEQ filter coefficients with the eigenvector; 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,

wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue, and

wherein the subspace of eigenvectors has a basis of eigenvectors corresponding to a set of eigenvalues that is comparable in magnitude to the maximum eigenvalue.

20. The computer readable medium of claim 19, 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.

21. The computer readable medium of claim 19, 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.

22. The computer readable medium of claim 19, 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 computer readable medium of claim 22, 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.

24. The computer readable medium of claim 22, 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.

25. The computer readable medium of claim 22, wherein the eigenvector used to compute the TEQ filter coefficients does not correspond to a maximum eigenvalue.

26. The computer readable medium of claim 22, 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.

27. The computer readable medium of claim 26, 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.

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

extracting in the DMT system a last portion of a prefix symbol;

shaping in the DMT system a prefix with a prefix window to create a shaped prefix;

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

combining in the DMT system the shaped DMT symbol and the shaped prefix,

wherein the combined shaped DMT symbol and shaped prefix generate a full rectangle symbol with a length less than or equal to a boundary prefix length.

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

extracting in the DMT system a last portion of a prefix symbol;

shaping in the DMT system a prefix with a prefix window to create a shaped prefix;

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

combining in the DMT system the shaped DMT symbol and the shaped prefix,

wherein the combined shaped DMT symbol and shaped prefix generate a full rectangle symbol with a length less than or equal to a boundary prefix length.