Wireless headset and method for robust voice data communication

• US 20070143105A1
• Filed: 12/16/2005
• Published: 06/21/2007
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Vocollect, Inc. (Honeywell International Inc.)
• Original Assignee: Vocollect, Inc. (Honeywell International Inc.)
• Inventors: Braho, Keith, El-Jaroudi, Amro, Byford, Roger, Kerr, Thomas
• Granted Patent: US 8,417,185 B2
• Time in Patent Office: Days
• US Class Current: 704/231
• CPC Class Codes: G10L 15/30 Distributed recognition, e.g. in client-server systems, for mobile phones or network applications

Abstract

A wireless device for use with speech recognition applications comprises a frame generator for generating successive frames from digitized original audio signals, the frames representing portions of the digitized audio signals. An autocorrelation circuit generates a set of coefficients for each frame, the coefficient set being reflective of spectral characteristics of the audio signal portion represented by the frame. In one embodiment, the autocorrelation coefficients may be used to predict the original audio signal to be subtracted from the original audio signals and to generate residual signals A Bluetooth transceiver is configured for transmitting the set of coefficients and/or residual signals as data to another device, which utilizes the coefficients for speech applications.

Claims

1. A wireless device for use with speech recognition applications:

comprising;

a frame generator for generating successive frames from a digitized audio signal, the frames representing portions of the digitized audio signal;

an autocorrelation circuit for generating a set of coefficients for each frame, the coefficient set being reflective of spectral characteristics of the audio signal portion represented by the frame;

a Bluetooth transceiver configured for transmitting the set of coefficients as data to another device to utilize for speech recognition applications.

2. The wireless device of claim 1 wherein the Bluetooth transceiver is operable for using an asynchronous connection-less (ACL) link for transmitting the set of coefficients to another device.

3. The wireless device of claim 1 comprising an A/D circuit for sampling an audio signal captured by the headset to form the digitized audio signal.

4. The wireless device of claim 3 wherein the A/D circuit is operable for sampling at a rate in the range of 11 KHz to 48 KHz.

5. The wireless device of claim 1 comprising a pre-emphasis circuit for emphasize higher frequency components of the digitized audio signal.

6. The wireless device of claim 5 wherein the pre-emphasis circuit is a filter.

7. The wireless device of claim 1 wherein the frame generator generates successive overlapping frames.

8. The wireless device of claim 1 wherein the frames generated are in the range of 10 ms to 100 ms in size.

9. The wireless device of claim 7 wherein the frames overlap with successive frames in an amount in the range or 0% to 50%.

10. The wireless device of claim 1 further comprising a windowing circuit for adjusting the digitized audio signal at the edges of the successive frames

11. The wireless device of claim 1 wherein the autocorrelation circuit generates a set of coefficients reflective of the spectral envelope of the audio signal portion represented by the frame.

12. The wireless device of claim 1 wherein the autocorrelation circuit generates a number of coefficients for each frame in the range of 10 to 21.

13. The wireless device of claim 1 wherein generated coefficients have a data size in the range or 16 to 32 bits per coefficient.

14. A wireless device for use with speech recognition applications comprising:

digital signal processing circuitry configured to generate sets of coefficients from a digitized audio signal, the coefficients being reflective of spectral characteristics of portions of the digitized audio signal;

a wireless transceiver configured for transmitting the sets of coefficients as data to another device to utilize for speech applications.

15. The wireless device of claim 14 wherein the wireless transceiver is a Bluetooth transceiver operable for using an asynchronous connection-less (ACL) link for transmitting the sets of coefficients to another device.

16. The wireless device of claim 14 wherein the digital signal processing circuitry is operable for generating successive frames from a digitized audio signal, the frames representing portions of the digitized audio signal.

17. The wireless device of claim 14 wherein the digital signal processing circuitry pre-emphasizes higher frequency components of the digitized audio signal prior to generating the sets of coefficients.

18. The wireless device of claim 16 wherein the frames generated are in the range of 10 ms to 100 ms in size.

19. The wireless device of claim 14 wherein the digital signal processing circuit is operable to perform a windowing application on the successive frames of the digitized audio signal for adjusting the digitized audio signal at the edges of the successive frames.

20. The wireless device of claim 14 wherein the set of coefficients is reflective of the spectral envelope of the audio signal portion represented by the frame.

21. The wireless device of claim 14 wherein digital signal processing circuit generates a number of coefficients for each frame in the range of 10 to 21.

22. The wireless device of claim 14 wherein the generated coefficients have a data size in the range or 16 to 32 bits per coefficient.

23. A wireless headset for use with speech applications comprising:

a microphone to capture an audio signal;

digital signal processing circuitry configured to generate sets of coefficients from a digitized audio signal, the coefficients being reflective of spectral characteristics of portions of the digitized audio signal;

a wireless transceiver configured for transmitting the sets of coefficients to another device to utilize for speech applications.

24. The wireless headset of claim 23 wherein the wireless transceiver is a Bluetooth transceiver operable for using an asynchronous connection-less (ACL) link for transmitting the sets of coefficients to another device.

25. The wireless headset of claim 23 wherein the digital signal processing circuitry is operable for generating successive frames from a digitized audio signal, the frames representing portions of the digitized audio signal.

26. The wireless headset of claim 23 wherein the digital signal processing circuitry pre-emphasizes higher frequency components of the digitized audio signal prior to generating the sets of coefficients.

27. The wireless headset of claim 25 wherein the frames generated are in the range of 10 ms to 100 ms in size.

28. The wireless headset of claim 23 wherein the digital signal processing circuit is operable to perform a windowing application on the successive frames of the digitized audio signal for adjusting the digitized audio signal at the edges of the successive frames.

29. The wireless headset of claim 23 wherein the set of coefficients is reflective of the spectral envelope of the audio signal portion represented by the frame.

30. The wireless headset of claim 23 wherein digital signal processing circuit generates a number of coefficients for each frame in the range of 10 to 21.

31. The wireless headset of claim 23 wherein the generated coefficients have a data size in the range or 16 to 32 bits per coefficient.

32. A method of transmitting voice information over a wireless link for use in speech applications, comprising:

capturing an audio signal and digitizing the audio signal;

generating a set of autocorrelation coefficients from the digitized audio signal, the coefficient set being reflective of spectral characteristics of the audio signal;

transmitting the set of coefficients as data to a device which utilizes the coefficients for speech recognition applications.

33. The method of claim 32 further comprising transmitting the coefficient data using a Bluetooth data transmission format.

34. The method of claim 33 further comprising transmitting with a Bluetooth format using an asynchronous connection-less (ACL) link.

35. The method of claim 32 further comprising generating successive frames from a digitized version of the audio signal, the frames representing portions of the digitized audio signal.

36. The method of claim 32 further comprising pre-emphasizing higher frequency components of the digitized audio signal prior to generating a set of autocorrelation coefficients.

37. The method of claim 32 further comprising generating successive overlapping frames.

38. The method of claim 32 wherein the frames generated are in the range of 10 ms to 100 ms in size.

39. The method of claim 38 wherein the frames overlap with successive frames in an amount in the range or 0% to 50%.

40. The method of claim 32 further comprising performing a windowing operation on the frames for adjusting the digitized audio signal at the edges of the successive frames.

41. The method of claim 32 wherein the generated set of autocorrelation coefficients are reflective of the spectral envelope of the audio signal portion represented by the frame.

42. The method of claim 32 further comprising generating wherein the autocorrelation circuit generates a number of coefficients for each frame in the range of 10 to 21.

43. The method of claim 32 wherein generated coefficients have a data size in the range or 16 to 32 bits per coefficient.

44. A wireless device for use with speech recognition applications comprising:

conversion circuitry for digitizing original audio signals to form digitized audio signals;

an autocorrelation circuit for generating a set of coefficients from the digitized audio signals, the coefficient set being reflective of spectral characteristics of the audio signals;

processing circuitry operable to use the autocorrelation coefficients for generating a predicted version of the audio signal and to subtract the predicted version from the original audio signals to generate residual signals;

a Bluetooth transceiver configured for transmitting the set of coefficients and the residual signals as data to another device to utilize for speech applications.

45. The wireless device of claim 44 wherein the processing circuitry generates prediction coefficients for the predicted version of the audio signal.

46. The wireless device of claim 44 wherein the Bluetooth transceiver is operable for using an asynchronous connection-less (ACL) link for transmitting the data to another device.

47. The wireless device of claim 44 wherein the processing circuitry is operable for normalizing the residual signals.

48. The wireless device of claim 44 further comprising an encoding circuit for encoding the residual signals for transmission.

49. The wireless device of claim 48 further wherein the encoding circuit encodes the residual signals with 2-10 bits.

50. A wireless system for use with speech applications comprising:

a transmitter including processing circuitry for digitizing original audio signals and generating a set of autocorrelation coefficients from the digitized audio signals reflective of spectral characteristics of the audio signals, the processing circuitry further operable for generating predicted versions of the audio signals from the autocorrelation coefficients and for subtracting the predicted versions from the original audio signals to generate residual signals;

a Bluetooth transceiver configured for transmitting the set of auto correlation coefficients and the residual signals as data; and

a receiver for receiving the data and processing the data for speech applications.

51. The system of claim 50 wherein the receiver is operable to use the autocorrelation values for speech recognition applications.

52. The system of claim 50 wherein the receiver is operable for using the autocorrelation values and residual signals to recreate audio signals reflective of the original audio signals.

53. The system of claim 52 wherein the receiver is operable for using the auto correlation coefficients to generate predicted versions of the audio signals and then to add the predicted versions to the residual signals to recreate audio signals reflective of the original audio signals.

54. A method of transmitting voice information over a wireless link for use in speech applications, comprising:

capturing an original audio signal and digitizing the audio signal;

generating a set of autocorrelation values from the digitized audio signal, the autocorrelation values set being reflective of spectral characteristics of the audio signal;

generating a predicted version of the audio signals with the autocorrelation values and subtracting the predicted version from the original audio signals to generate residual signals;

transmitting the set of coefficients and the residual signals as data to another device to utilize for speech applications.

55. The method of claim 54 further comprising transmitting the data using a Bluetooth data transmission format.

56. The method of claim 55 further comprising transmitting with a Bluetooth format using an asynchronous connection-less (ACL) link.