PACKET LOSS MITIGATION IN TRANSMISSION OF BIOMEDICAL SIGNALS FOR HEALTHCARE AND FITNESS APPLICATIONS

• US 20100246651A1
• Filed: 07/30/2009
• Published: 09/30/2010
• Est. Priority Date: 03/31/2009
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Garudadri, Harinath, Baheti, Pawan Kumar
• Application Number:
  US12/512,744
• Publication Number:
  US 20100246651A1
• Time in Patent Office: Days
• US Class Current: 375/224
• 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

Abstract

Certain aspects of the present disclosure relate to a method for compressed sensing (CS). The CS is a signal processing concept wherein significantly fewer sensor measurements than that suggested by Shannon/Nyquist sampling theorem can be used to recover signals with arbitrarily fine resolution. In this disclosure, the CS framework is applied for sensor signal processing in order to support low power robust sensors and reliable communication in Body Area Networks (BANs) for healthcare and fitness applications.

Claims

1. A method for signal processing, comprising:

sensing samples of a signal;

preceding the sensed samples to obtain a precoded signal;

packetizing the precoded signal to obtain at least one packet of the precoded signal; and

transmitting the at least one packet of the precoded signal over a wireless channel.

2. The method of claim 1, wherein sensing samples of the signal comprises sampling the signal at non-uniform discrete time intervals, and wherein at least one time interval from the non-uniform discrete time intervals is different than at least another time interval from the non-uniform discrete time intervals.

3. The method of claim 1, wherein sensing samples of the signal comprises sampling the signal at uniform discrete time intervals.

4. The method of claim 1, wherein preceding the sensed samples comprises:

preceding a defined number of the sensed samples to obtain a set of precoded samples; and

performing sample-level interleaving over the set of precoded samples.

5. The method of claim 1, wherein preceding the sensed samples comprises:

creating a measurement matrix of size K×

N; and

multiplying the sensed samples with the measurement matrix; and

wherein N is a number of the sensed samples, K is a number of precoded samples.

6. The method of claim 5, wherein creating the measurement matrix comprises utilizing a random seed to create the measurement matrix same as another measurement matrix used for reconstruction of the signal at another side of a communication link, and wherein the random seed was received from the other side of the communication link.

7. The method of claim 5, wherein elements of the measurement matrix are chosen from the symmetric Bernoulli distribution.

8. The method of claim 1, wherein the signal comprises a biomedical signal.

9. The method of claim 8, wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electro-cardiogram (ECG) signal.

10. An apparatus for signal processing, comprising:

a sensor configured to generate sensed samples of a signal;

an encoder configured to precode the sensed samples to obtain a precoded signal;

a packetizing circuit configured to packetize the precoded signal to obtain at least one packet of the precoded signal; and

a transmitter configured to transmit the at least one packet of the precoded signal over a wireless channel.

11. The apparatus of claim 10, wherein the sensor configured to generate sensed samples of the signal comprises a circuit for sampling the signal at non-uniform discrete time intervals, and wherein at least one time interval from the non-uniform discrete time intervals is different than at least another time interval from the non-uniform discrete time intervals.

12. The apparatus of claim 10, wherein the sensor configured to generate sensed samples of the signal comprises a circuit for sampling the signal at uniform discrete time intervals.

13. The apparatus of claim 10, wherein the encoder configured to precode the sensed samples comprises:

a preceding circuit configured to precode a defined number of the sensed samples to obtain a set of precoded samples; and

an interleaver configured to perform sample-level interleaving over the set of precoded samples.

14. The apparatus of claim 10, wherein the encoder configured to precode the sensed samples comprises:

a circuit configured to create a measurement matrix of size K×

N; and

a multiplier configured to multiply the sensed samples with the measurement matrix; and

wherein N is a number of the sensed samples, K is a number of precoded samples

15. The apparatus of claim 14, wherein the circuit configured to create the measurement matrix comprises a circuit configured to utilize a random seed to create the measurement matrix same as another measurement matrix used for reconstruction of the signal at another side of a communication link, and wherein the random seed was received from the other side of the communication link.

16. The apparatus of claim 14, wherein elements of the measurement matrix are chosen from the symmetric Bernoulli distribution.

17. The apparatus of claim 10, wherein the signal comprises a biomedical signal.

18. The apparatus of claim 17, wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electrocardiogram (ECG) signal.

19. An apparatus for signal processing, comprising:

means for generating sensed samples of a signal;

means for preceding the sensed samples to obtain a precoded signal;

means for packetizing the precoded signal to obtain at least one packet of the precoded signal; and

means for transmitting the at least one packet of the precoded signal over a wireless channel.

20. The apparatus of claim 19, wherein the means for generating sensed samples of the signal comprises means for sampling the signal at non-uniform discrete time intervals, and wherein at least one time interval from the non-uniform discrete time intervals is different than at least another time interval from the non-uniform discrete time intervals.

21. The apparatus of claim 19, wherein the means for generating sensed samples of the signal comprises means for sampling the signal at non-uniform discrete time intervals.

22. The apparatus of claim 19, wherein the means for preceding the sensed samples comprises:

means for preceding a defined number of the sensed samples to obtain a set of precoded samples; and

means for performing sample-level interleaving over the set of precoded samples.

23. The apparatus of claim 19, wherein the means for preceding the sensed samples comprises:

means for creating a measurement matrix of size K×

N; and

means for multiplying the acquired samples with the measurement matrix; and

wherein N is a number of the acquired samples, K is a number of precoded samples.

24. The apparatus of claim 23, wherein the means for creating the measurement matrix comprises means for utilizing a random seed to create the measurement matrix same as another measurement matrix used for reconstruction of the signal at another side of a communication link, and wherein the random seed was received from the other side of the communication link.

25. The apparatus of claims 23, wherein elements of the measurement matrix are chosen from the symmetric Bernoulli distribution.

26. The apparatus of claim 19, wherein the signal comprises a biomedical signal.

27. The apparatus of claim 26, wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electrocardiogram (ECG) signal.

28. A computer-program product for signal processing, comprising a computer-readable medium comprising instructions executable to:

sense samples of a signal;

precode the sensed samples to obtain a precoded signal;

packetize the precoded signal to obtain at least one packet of the precoded signal; and

transmit the at least one packet of the precoded signal over a wireless channel.

29. A sensing device, comprising:

at least one antenna;

a sensor configured to generate sensed samples of a signal;

an encoder configured to precode the sensed samples to obtain a precoded signal;

a packetizing circuit configured to packetize the precoded signal to obtain at least one packet of the precoded signal; and

a transmitter configured to transmit via the at least one antenna the at least one packet of the precoded signal over a wireless channel.

30. A method for signal processing, comprising:

receiving a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

identifying one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost; and

processing the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal.

31. The method of claim 30, wherein processing the received signal further comprises de-interleaving the received signal.

32. The method of claim 30, wherein processing the received signal comprises setting the estimated samples to zero values, if each packet of the at least one packet of samples is lost during the transmission.

33. The method of claim 30, wherein processing the received signal comprises receiving a random seed, said method further comprising:

constructing a measurement matrix based on the received random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal preceding before the transmission; and

using a matching pursuit (MP) algorithm based on the measurement matrix to estimate the original transmitted samples, if some but not all packets of the at least one packet of samples are corrupted or lost during the transmission.

34. The method of claim 33, further comprising:

sending feedback information to the transmission side to adapt the other measurement matrix used for precoding another signal before transmission.

35. The method of claim 34, wherein the feedback information comprises at least one of:

information whether each packet of the at least one packet of samples is successfully received or dropped during the transmission, a ratio of l₂-norm of a residual of the MP algorithm and l₂-norm of the received signal, or an iteration number of the MP algorithm.

36. The method of claim 30, wherein processing the received signal comprises receiving a random seed, said method further comprising:

constructing a measurement matrix based on the random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal precoding before the transmission; and

using a pseudo-inverse of the measurement matrix to estimate the original transmitted samples, if no packet from the at least one packet of samples is corrupted or lost during the transmission.

37. The method of claim 36, wherein elements of the measurement matrix are from the symmetric Bernoulli distribution, and wherein the measurement matrix is of size K×

N, where N is a number of transmitted samples, and K is a number of precoded samples before the transmission.

38. The method of claim 30, wherein the received signal comprises a biomedical signal.

39. The method of claim 38, and wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electro-cardiogram (ECG) signal.

40. An apparatus for signal processing, comprising:

a receiver configured to receive a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

a circuit configured to identify one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost; and

a processor configured to process the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal.

41. The apparatus of claim 40, wherein the processor configured to process the received signal comprises a de-interleaver configured to de-interleave the received signal.

42. The apparatus of claim 40, wherein the processor configured to process the received signal comprises a circuit configured to set the estimated samples to zero values, if each packet of the at least one packet of samples is lost during the transmission.

43. The apparatus of claim 40, wherein the processor configured to process the received signal comprises a circuit configured to receive a random seed, said circuit is further configured to:

construct a measurement matrix based on the received random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal preceding before the transmission; and

use a matching pursuit (MP) algorithm based on the measurement matrix to estimate the original transmitted samples, if some but not all packets of the at least one packet of samples are corrupted or lost during the transmission.

44. The apparatus of claim 43, further comprising:

a circuit configured to send feedback information to the transmission side to adapt the other measurement matrix used for preceding another signal before transmission.

45. The apparatus of claim 44, wherein the feedback information comprises at least one of:

information whether each packet of the at least one packet of samples is successfully received or dropped during the transmission, a ratio of l₂-norm of a residual of the MP algorithm and l₂-norm of the received signal, or an iteration number of the MP algorithm.

46. The apparatus of claim 40, wherein the processor configured to process the received signal comprises a circuit configured to receive a random seed, said circuit is further configured to:

construct a measurement matrix based on the random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal preceding before the transmission; and

use a pseudo-inverse of the measurement matrix to estimate the original transmitted samples, if no packet from the at least one packet of samples is corrupted or lost during the transmission.

47. The apparatus of claim 46, wherein elements of the measurement matrix are from the symmetric Bernoulli distribution, and wherein the measurement matrix is of size K×

N, where N is a number of transmitted samples, and K is a number of precoded samples before the transmission.

48. The apparatus of claim 40, wherein the received signal comprises a biomedical signal.

49. The apparatus of claim 48, wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electro-cardiogram (ECG) signal.

50. An apparatus for signal processing, comprising:

means for receiving a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

means for identifying one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost; and

means for processing the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal.

51. The apparatus of claim 50, wherein the means for processing the received signal further comprises means for de-interleaving the received signal.

52. The apparatus of claim 50, wherein the means for processing the received signal comprises means for setting the estimated samples to zero values, if each packet of the at least one packet of samples is lost during the transmission.

53. The apparatus of claim 50, wherein the means for processing the received signal comprises means for receiving a random seed, said means further comprising:

means for constructing a measurement matrix based on the received random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal preceding before the transmission; and

means for using a matching pursuit (MP) algorithm based on the measurement matrix to estimate the original transmitted samples, if some but not all packets of the at least one packet of samples are corrupted or lost during the transmission.

54. The apparatus of claim 53, further comprising:

means for sending feedback information to the transmission side to adapt the other measurement matrix used for precoding another signal before transmission.

55. The apparatus of claim 54, wherein the feedback information comprises at least one of:

information whether each packet of the at least one packet of samples is successfully received or dropped during the transmission, a ratio of l₂-norm of a residual of the MP algorithm and l₂-norm of the received signal, or an iteration number of the MP algorithm.

56. The apparatus of claim 50, wherein the means for processing the received signal comprises means for receiving a random seed, said means further comprising:

means for constructing a measurement matrix based on the random seed, wherein the constructed measurement matrix is same as another measurement matrix used for signal precoding before the transmission; and

means for using a pseudo-inverse of the measurement matrix to estimate the original transmitted samples, if no packet from the at least one packet of samples is corrupted or lost during the transmission.

57. The apparatus of claim 56, wherein elements of the measurement matrix are from the symmetric Bernoulli distribution, and wherein the measurement matrix is of size K×

N, where N is a number of transmitted samples, and K is a number of precoded samples before the transmission.

58. The apparatus of claim 50, wherein the received signal comprises a biomedical signal.

59. The apparatus of claim 58, wherein the biomedical signal comprises a photoplethysmograph (PPG) signal or an electro-cardiogram (ECG) signal.

60. A computer-program product for signal processing, comprising a computer-readable medium comprising instructions executable to:

receive a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

identify one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost; and

process the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal.

61. A headset, comprising:

a receiver configured to receive a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

a circuit configured to identify one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost;

a processor configured to process the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal; and

a transducer configured to provide an audio output based on the estimated signal.

62. A watch, comprising:

a receiver configured to receive a signal, wherein the signal was transmitted over a channel as at least one packet of samples;

a circuit configured to identify one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost;

a processor configured to process the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal; and

a user interface configured to provide an indication based on the estimated signal.

63. A monitoring device, comprising:

a connector;

a receiver configured to receive via the connector a signal, wherein the signal was transmitted as at least one packet of samples;

a circuit configured to identify one or more indices of the at least one packet of samples that is corrupted or lost during the transmission, if the at least one packet of samples is corrupted or lost;

a processor configured to process the received signal using the identified one or more indices of the at least one packet of samples that is corrupted or lost during the transmission to estimate the transmitted signal; and

a user interface configured to provide an indication based on the estimated signal.