System and method for processing data from and for multiple channels

• US 6,493,666 B2
• Filed: 07/21/1999
• Issued: 12/10/2002
• Est. Priority Date: 09/29/1998
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Covington & Burling LLP
• Inventors: Wiese, William M. Jr.
• Primary Examiner(s): Dorvil, Richemond
• Assistant Examiner(s): Chawan, Vijay B
• Application Number:
  US09/357,858
• Publication Number:
  US 20010027392A1
• Time in Patent Office: 1,238 Days
• Field of Search: 704/230, 704/201, 704/208, 704/214, 704/219, 704/220, 704/224, 704/223, 704/222, 704/500-504
• US Class Current: 704/230
• CPC Class Codes: G10L 19/00 Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis in musical instruments G10H
• CPC Class Codes: G10L 19/16 Vocoder architecture

Abstract

This invention takes advantage of the potential for a group of data channels, especially if they are carrying a related form of information such as human telephone conversations, to be compressed for transmission as a group to a greater degree than if the channels were compressed individually. A focus of the system and method of this invention is the organization of data from multiple channels, before the data are compressed for transmission, thereby taking advantage of redundant, extraneous or unnecessary information in common among the data. In a preferred embodiment, the invention organizes and processes human speech data from multiple voice-grade telephone channels into a highly compressed representation for transport by a packet switched network, and receives and processes those highly compressed representations to reconstruct, exactly or approximately, the human speech data. This embodiment thus provides for efficient bulk transport of multiple voice-grade telephone channels through a packet switched network. More generally, the present invention provides a system and method for processing data from multiple channels into alternate representations in order to facilitate efficient transmission. The invention more generally also provides a system and method for processing such alternate representations in order to reconstruct, exactly or approximately, data for transmission on multiple channels.

Claims

1. A system for processing data from multiple channels, comprising:

a first transformer having

means for receiving a plurality of source-identified-frames, and

means for transforming at least one source-identified-frame into at least one transformed-source-identified-frame;

a classifier, in communication with the first transformer, having

means for receiving at least one transformed-source-identified-frame from the first transformer,

means for categorizing at least one transformed-source-identified-frame by domain type wherein there is at least one prespecified domain type,

means for categorizing at least one transformed-source-identified-frame by category type wherein there is at least one prespecified category type,

means, responsive to the domain type and the category type of at least one transformed-source-identified-frame, for grouping at least one transformed-source-identified-frame into at least one frame-block;

a second transformer, in communication with the classifier, having

means for receiving at least one frame-block from the classifier, and

means for transforming at least one frame-block into at least one transformed-frame-block; and

a postprocessor, in communication with the second transformer and a

transmission network, having

means for receiving at least one transformed-frame-block from the second transformer,

means for compressing at least one transformed-frame-block into at least one data-stream, and

means for transmitting at least one data-stream to the transmission network.

2. The system for processing data from multiple channels of claim 1, wherein the source-identified-frames comprise speech-type data, and the transforming means of the first transformer comprises means for converting at least one source-identified-frame into at least one transformed-source-identified-frame having a first domain type related to vocal-tract parameters and at least one transformed-source-identified-frame having a second domain type related to residual excitation signals.

3. The system for processing data from multiple channels of claim 2, wherein at least one transformed-source-identified-frame having the first domain type related to vocal-tract parameters comprises a line spectra including at least one line-spectra-value.

4. The system for processing data from multiple channels of claim 3 wherein the grouping means of the classifier comprises means for arranging the transformed-source-identified-frames grouped into at least one frame-block.

5. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for averaging the line-spectra-values of each transformed-source-identified-frame that comprises line spectra and that is grouped into at least one frame-block, and wherein the arranging means is responsive to the averaging means.

6. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for selecting, in accordance with predefined criteria, a subset of the line-spectra-values of each transformed-source-identified-frame that comprises line spectra and that is grouped into at least one frame-block, and means for averaging the subset of the line-spectra-values;

and wherein the arranging means is responsive to the averaging means.

7. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for associating an average-frame-energy with each transformed-source-identified-frame that is grouped into at least one frame-block;

and wherein the arranging means is responsive to the average-frame-energy associating means.

8. The system for processing data from multiple channels of claim 7 wherein the average-frame-energy associating means is responsive to an average-frame-energy of each transformed-source-identified-frame having a second domain type related to residual excitation signals and that is grouped into at least one frame-block.

9. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for associating an average-frame-energy with each source-identified-frame and wherein the arranging means is responsive to the average-frame-energy associating means.

10. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for associating a zero-crossing-rate with each transformed-source-identified-frame having a second domain type related to residual excitation signals and that is grouped into at least one frame-block;

and wherein the arranging means is responsive to the zero-crossing-rate associating means.

11. The system for processing data from multiple channels of claim 4 wherein the arranging means comprises means for associating a zero-crossing-rate with each source-identified-frame and wherein the arranging means is responsive to the zero-crossing-rate associating means.

12. The system for processing data from multiple channels of claim 2, wherein at least one category type relates to fully-silent-type transformed-source-identified-frames, at least one category type relates to voiced-type transformed-source-identified-frames, and at least one category type relates to unvoiced-type transformed-source-identified-frames.

13. The system for processing data from multiple channels of claim 1, wherein the transforming means of the second transformer comprises a forward two-dimensional transform.

14. The system for processing data from multiple channels of claim 13, wherein the forward two-dimensional transform comprises a transform selected from the group consisting of a Fourier transform, a Fast Fourier transform, a wavelet transform, a DST transform, a DCT transform, a Haar transform, a Walsh transform, and a KLT transform.

15. The system for processing data from multiple channels of claim 1, wherein the compressing means of the postprocessor comprises means for converting at least one transformed-frame-block to a differential representation.

16. The system for processing data from multiple channels of claim 1, further comprising a preprocessor, in communication with the first transformer, having

means for receiving a plurality of data channels, and

means for segmenting at least one data channel into a plurality of source-identified-frames.

17. A system for processing data for multiple channels, comprising:

a preprocessor, in communication with a transmission network, having

means for receiving at least one data-stream from the transmission network, and

means for decompressing at least one data-stream into at least one transformed-frame-block;

a first inverse-transformer, in communication with the preprocessor, having

means for receiving at least one transformed-frame-block from the preprocessor, and

means for inverse-transforming at least one transformed-frame-block into at least one frame-block;

an assembler, in communication with the first inverse-transformer, having

means for receiving at least one frame-block from the first inverse-transformer, and

means for separating at least one frame-block into at least one transformed-source-identified-frame; and

a second inverse-transformer, in communication with the assembler, and having

means for receiving at least one transformed-source-identified-frame from the assembler, and

means for inverse-transforming at least one transformed-source-identifed-frame into at least one source-identified-frame.

18. The system for processing data for multiple channels of claim 17, wherein the inverse-transforming means of the first inverse-transformer comprises an inverse two-dimensional transform.

19. The system for processing data for multiple channels of claim 18, wherein the inverse two-dimensional transform comprises a transform that is selected from the group consisting of a Fourier transform, a Fast Fourier transform, a wavelet transform, a DST transform, a DCT transform, a Haar transform, a Walsh transform, and a KLT transform.

20. The system for processing data for multiple channels of claim 17, wherein the inverse-transforming means of the second inverse-transformer comprises an inverse LPC transform.

21. The system for processing data for multiple channels of claim 17, further comprising a postprocessor, in communications with the second inverse-transformer, having

means for receiving at least one source-identified-frame, and

means, responsive to at least one source-identified-frame, for combining at least one source-identified-frame into at least one data channel.

22. A method for processing data from multiple channels, comprising the steps of:

receiving a plurality of source-identified-frames;

transforming at least one source-identified-frame into at least one transformed-source-identified-frame;

categorizing at least one transformed-source-identified-frame by domain type wherein there is at least one prespecified domain type;

categorizing at least one transformed-source-identified-frame by category type wherein there is at least one prespecified category type;

grouping, responsive to the domain type and the category type of at least one transformed-source-identified-frame, at least one transformed-source-identified-frame into at least one frame-block;

transforming at least one frame-block into at least one transformed-frame-block;

compressing at least one transformed-frame-block into at least one data-stream; and

transmitting at least one data-stream to a transmission network.

23. The method of processing data from multiple channels of claim 22, wherein the source-identified-frames comprise speech-type data, and the source-identified-frame transforming step comprises the step of converting at least one source-identified-frame into at least one transformed-source-identified-frame having a first domain type related to vocal-tract parameters and at least one transformed-source-identified-frame having a second domain type related to residual excitation signals.

24. The method of processing data from multiple channels of claim 23, wherein at least one transformed-source-identified-frame having the first domain type related to vocal-tract parameters comprises a line spectra including at least one line-spectra-value.

25. The method of processing data from multiple channels of claim 24, wherein the grouping step comprises the step of arranging the transformed-source-identified-frames grouped into at least one frame-block.

26. The method of processing data from multiple channels of claim 25, wherein the arranging step comprises the step of averaging the line-spectra-values of each transformed-source-identified-frame that comprises line spectra and that is grouped into at least one frame-block, and wherein the arranging step is responsive to the averaging step.

27. The method of processing data from multiple channels of claim 25 wherein the arranging step comprises the step of selecting, in accordance with predefined criteria, a subset of the line-spectra-values of each transformed-source-identified-frame that comprises line spectra and that is grouped into at least one frame-block, and the step of averaging the subset of the line-spectra-values;

and wherein the arranging step is responsive to the averaging step.

28. The method of processing data from multiple channels of claim 25 wherein the arranging step comprises the step of associating an average-frame-energy with each transformed-source-identified-frame that is grouped into at least one frame-block;

and wherein the arranging step is responsive to the average-frame-energy associating step.

29. The method of processing data from multiple channels of claim 28 wherein the average-frame-energy associating step is responsive to an average-frame-energy of each transformed-source-identified-frame having a second domain type related to residual excitation signals and that is grouped into at least one frame-block.

30. The method of processing data from multiple channels of claim 25 wherein the arranging step comprises the step of associating an average-frame-energy with each source-identified-frame and wherein the arranging step is responsive to the average-frame-energy associating step.

31. The method of processing data from multiple channels of claim 25 wherein the arranging step comprises the step of associating an zero-crossing-rate with each transformed-source-identified-frame having a second domain type related to residual excitation signals and that is grouped into at least one frame-block;

and wherein the arranging step is responsive to the zero-crossing-rate associating step.

32. The method of processing data from multiple channels of claim 25 wherein the arranging step comprises the step of associating a zero-crossing-rate with each source-identified-frame and wherein the arranging step is responsive to the zero-crossing-rate associating step.

33. The method of processing data from multiple channels of claim 23, wherein at least one category type relates to fully-silent-type transformed-source-identified-frames, at least one category type relates to voiced-type transformed-source-identified-frames, and at least one category type relates to unvoiced-type transformed-source-identified-frames.

34. The method of processing data from multiple channels of claim 22, wherein the frame-block transforming step comprises a forward two-dimensional transform.

35. The method of processing data from multiple channels of claim 34, wherein the forward two-dimensional transform comprises a transform selected from the group consisting of a Fourier transform, a Fast Fourier transform, a wavelet transform, a DST transform, a DCT transform, a Haar transform, a Walsh transform, and a KLT transform.

36. The method of processing data from multiple channels of claim 22, wherein the step of compressing at least one transformed-frame-block comprises the step of converting at least one transformed-frame-block to a differential representation.

37. The method of processing data from multiple channels of claim 22, further comprising the steps of

receiving a plurality of data channels;

segmenting at least one data channel into a plurality of source-identified-frames; and

transmitting the plurality of source-identified-frames.

38. A method of processing data for multiple channels, comprising the steps of:

receiving at least one data-stream from a transmission network;

decompressing at least one data-stream into at least one transformed-frame-block;

inverse-transforming at least one transformed-frame-block into at least one frame-block;

separating at least one frame-block into at least one transformed-source-identified-frame; and

inverse-transforming at least one transformed-source-identified-frame into at least one source-identified-frame.

39. The method of processing data for multiple channels of claim 38, wherein the transformed-frame-block inverse-transforming step comprises an inverse two-dimensional transform.

40. The method of processing data for multiple channels of claim 39, wherein the inverse two-dimensional transform comprises a transform that is selected from the group consisting of a Fourier transform, a Fast Fourier transform, a wavelet transform, a DST transform, a DCT transform, a Haar transform, a Walsh transform, and a KLT transform.

41. The method of processing data for multiple channels of claim 38, wherein the transformed-source-identified-frame inverse-transforming step comprises an inverse LPC transform.

42. The method of processing data for multiple channels of claim 38, further comprising the step of combining, responsive to at least one source-identified-frame, at least one source-identified-frame into at least one data channel.