Method and apparatus for low complexity compression of signals

• US 9,136,980 B2
• Filed: 08/30/2011
• Issued: 09/15/2015
• Est. Priority Date: 09/10/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Baheti, Pawan Kumar, Garudadri, Harinath, Chi, Yuejie
• Primary Examiner(s): PULLIAS, JESSE SCOTT
• Application Number:
  US13/221,633
• Publication Number:
  US 20120224611A1
• Time in Patent Office: 1,477 Days
• Field of Search: 704200-230, 704500-504
• US Class Current: 1/1
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H04L 1/0043 Realisations of complexity reduction techniques, e.g. use of look-up tables
• CPC Class Codes: H04L 1/0052 Realisations of complexity reduction techniques, e.g. pipelining or use of look-up tables
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability

Abstract

Certain aspects of the present disclosure relate to techniques for low-complexity encoding (compression) of broad class of signals, which are typically not well modeled as sparse signals in either time-domain or frequency-domain. First, the signal can be split in time-segments that may be either sparse in time domain or sparse in frequency domain, for example by using absolute second order differential operator on the input signal. Next, different encoding strategies can be applied for each of these time-segments depending in which domain the sparsity is present.

Claims

1. An apparatus for communication, comprising:

a first circuit configured to detect one or more transient segments of a biomedical signal, wherein the first circuit is also configured to apply a second-order differential on the biomedical signal to detect the one or more transient segments;

a second circuit configured to estimate a residual segment of the biomedical signal based on the one or more transient segments;

a first encoder configured to encode the one or more transient segments;

a second encoder configured to encode the residual segment; and

a transmitter configured to transmit the one or more encoded transient segments and the encoded residual segment.

2. The apparatus of claim 1, wherein the first circuit is also configured to:

identify at least one sample of the biomedical signal having a value of the second-order differential larger than a threshold; and

select a window of samples of the biomedical signal around each of the at least one sample to detect the one or more transient segments.

3. The apparatus of claim 1, wherein the first encoder is also configured to encode the transient segments by encoding segments of the biomedical signal being sparse in time domain.

4. The apparatus of claim 3, wherein encoding the segments of the biomedical signal being sparse in time domain comprises sensing inflection points of the biomedical signal.

5. The apparatus of claim 1, wherein the second circuit is also configured to:

replace, in the biomedical signal, samples of the transient segments with values to estimate the residual segment.

6. The apparatus of claim 5, wherein the values comprise all zeros.

7. The apparatus of claim 5, wherein the values are defined to form one or more smooth segments replacing the one or more transient segments.

8. The apparatus of claim 1, wherein the second encoder is also configured to:

perform, in time domain, random sampling of the residual segment to encode the residual segment.

9. The apparatus of claim 1, wherein the second encoder is also configured to:

determine whether the residual segment comprises a low-pass signal; and

perform decimation on the residual segment, if the residual segment comprises the low-pass signal.

10. The apparatus of claim 9, further comprising:

a finite impulse response (FIR) filter configured to filter the residual segment prior to the decimation.

11. The apparatus of claim 1, wherein the second encoder is also configured to:

determine whether the residual segment comprises a low-pass signal; and

perform random sampling of the residual segment, if the residual segment does not comprise the low-pass signal.

12. A method for communication, comprising:

detecting one or more transient segments of a biomedical signal by at least applying a second-order differential on the biomedical signal to detect the one or more transient segments;

estimating a residual segment of the biomedical signal based on the one or more transient segments;

encoding the one or more transient segments;

encoding the residual segment; and

transmitting the one or more encoded transient segments and the encoded residual segment.

13. The method of claim 12, further comprising:

identifying at least one sample of the biomedical signal having a value of the second-order differential larger than a threshold; and

selecting a window of samples of the biomedical signal around each of the at least one sample to detect the one or more transient segments.

14. The method of claim 12, wherein encoding the transient segments comprises:

encoding segments of the biomedical signal being sparse in time domain.

15. The method of claim 14, wherein encoding the segments of the biomedical signal being sparse in time domain comprises sensing inflection points of the biomedical signal.

16. The method of claim 12, further comprising:

replacing, in the biomedical signal, samples of the transient segments with values to estimate the residual segment.

17. The method of claim 16, wherein the values comprise all zeros.

18. The method of claim 16, wherein the values are defined to form one or more smooth segments replacing the one or more transient segments.

19. The method of claim 12, wherein encoding the residual segment comprises:

performing, in time domain, random sampling of the residual segment.

20. The method of claim 12, wherein encoding the residual segment comprises:

determining whether the residual segment comprises a low-pass signal; and

performing decimation on the residual segment, if the residual segment comprises the low-pass signal.

21. The method of claim 20, further comprising:

finite impulse response (FIR) filtering of the residual segment prior to the decimation.

22. The method of claim 12, wherein encoding the residual segment comprises:

determining whether the residual segment comprises a low-pass signal; and

performing random sampling of the residual segment, if the residual segment does not comprise the low-pass signal.

23. An apparatus for communication, comprising:

means for detecting one or more transient segments of a biomedical signal, said detecting means comprising means for applying a second-order differential on the biomedical signal to detect the one or more transient segments;

means for estimating a residual segment of the biomedical signal based on the one or more transient segments;

means for encoding the one or more transient segments;

means for encoding the residual segment; and

means for transmitting the one or more encoded transient segments and the encoded residual segment.

24. The apparatus of claim 23, further comprising:

means for identifying at least one sample of the biomedical signal having a value of the second-order differential larger than a threshold; and

means for selecting a window of samples of the biomedical signal around each of the at least one sample to detect the one or more transient segments.

25. The apparatus of claim 23, wherein the means for encoding the transient segments comprises:

means for encoding segments of the biomedical signal being sparse in time domain.

26. The apparatus of claim 25, wherein the means for encoding the segments of the biomedical signal being sparse in time domain comprises:

means for sensing inflection points of the biomedical signal.

27. The apparatus of claim 23, further comprising:

means for replacing, in the biomedical signal, samples of the transient segments with values to estimate the residual segment.

28. The apparatus of claim 27, wherein the values comprise all zeros.

29. The apparatus of claim 27, wherein the values are defined to form one or more smooth segments replacing the one or more transient segments.

30. The apparatus of claim 23, wherein the means for encoding the residual segment comprises:

means for performing, in time domain, random sampling of the residual segment.

31. The apparatus of claim 23, wherein the means for encoding the residual segment comprises:

means for determining whether the residual segment comprises a low-pass signal; and

means for performing decimation on the residual segment, if the residual segment comprises the low-pass signal.

32. The apparatus of claim 31, further comprising:

means for finite impulse response (FIR) filtering of the residual segment prior to the decimation.

33. The apparatus of claim 23, wherein the means for encoding the residual segment comprises:

means for determining whether the residual segment comprises a low-pass signal; and

means for performing random sampling of the residual segment, if the residual segment does not comprise the low-pass signal.

34. A computer-program product for communication, comprising a non-transitory computer-readable medium comprising instructions executable to:

detect one or more transient segments of a biomedical signal by at least applying a second-order differential on the biomedical signal to detect the one or more transient segments;

estimate a residual segment of the biomedical signal based on the one or more transient segments;

encode the one or more transient segments;

encode the residual segment; and

transmit the one or more encoded transient segments and the encoded residual segment.

35. A sensing device, comprising:

a sensor configured to sense a biomedical signal;

a first circuit configured to detect one or more transient segments of the biomedical signal, wherein the first circuit is also configured to apply a second-order differential on the biomedical signal to detect the one or more transient segments;

a second circuit configured to estimate a residual segment of the biomedical signal based on the one or more transient segments;

a first encoder configured to encode the one or more transient segments;

a second encoder configured to encode the residual segment; and

a transmitter configured to transmit the one or more encoded transient segments and the encoded residual segment.