Interference Mitigation For Impulse-Based Communication

• US 20090080542A1
• Filed: 09/25/2007
• Published: 03/26/2009
• Est. Priority Date: 09/25/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ekbal, Amal, Julian, David Jonathan
• Granted Patent: US 8,233,572 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/24 Testing correct operation

Abstract

In a pulse-based communication system a transmitting device may generate a series of pulses to convey information via a communication medium to a receiving device. In some situations, interference from one or more interfering devices may alter the pulse energy as it is transmitted through the communication medium. To mitigate the effect of such interference, a receiving device may mark certain received pulses as erasures. In this way, such pulses may be ignored during the decoding operation of the receiver.

Claims

1. A method of erasure detection, comprising

receiving at least one pulse signal;

comparing at least one characteristic of the at least one pulse signal with at least one threshold; and

designating the at least one pulse signal as at least one erasure based on the comparison.

2. The method of claim 1, wherein the at least one characteristic of the at least one pulse signal relates to at least one of the group consisting of:

signal strength of the at least one pulse signal;

amplitude of the at least one pulse signal;

phase of the at least one pulse signal;

frequency of the at least one pulse signal; and

bandwidth of the at least one pulse signal.

3. The method of claim 1, further comprising defining the at least one threshold based on at least one characteristic of previously received pulse signals.

4. The method of claim 3, wherein the at least one threshold comprises:

an average of the at least one characteristic of the previously received pulse signals,

a windowed mean of the at least one characteristic of the previously received pulse signals,

a weighted mean of the at least one characteristic of the previously received pulse signals, or

a median of the at least one characteristic of the previously received pulse signals.

5. The method of claim 3, wherein the at least one characteristic of the previously received pulse signals relates to at least one of the group consisting of:

signal strength of the previously received pulse signals;

amplitude of the previously received pulse signals;

phase of the previously received pulse signals;

frequency of the previously received pulse signals; and

bandwidth of the previously received pulse signals.

6. The method of claim 1, further comprising defining the at least one threshold based on successful reception of packets.

7. The method of claim 1, further comprising repeatedly adapting the at least one threshold.

8. The method of claim 1, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is greater than or equal to the at least one threshold.

9. The method of claim 1, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is less than or equal to the at least one threshold.

10. The method of claim 1, wherein the comparison is based on:

an infinite impulse response filtered value of the at least one characteristic of the at least one pulse signal;

or

a finite impulse response filtered value of the at least one characteristic of the at least one pulse signal.

11. The method of claim 1, wherein the at least one erasure comprises a Viterbi decision metric for a convolutional code.

12. The method of claim 1, wherein the designation of the received at least one pulse signal as at least one erasure is based on at least one previous comparison of another at least one pulse signal with the at least one threshold.

13. The method of claim 1, wherein the at least one pulse signal comprises at least one pulse position modulated signal.

14. The method of claim 13, wherein the comparison comprises comparing the at least one threshold with energy detected at at least one pulse position defined for the at least one pulse position modulated signal.

15. The method of claim 13, further comprising:

summing energy levels detected at different pulse positions defined for the at least one pulse position modulated signal;

wherein the comparison comprises comparing the summed energy levels with the at least one threshold.

16. The method of claim 1, wherein the at least one pulse signal comprises a plurality of pulse signals.

17. The method of claim 16, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is greater than or equal to the at least one threshold.

18. The method of claim 16, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is less than or equal to the at least one threshold.

19. The method of claim 16, wherein the comparison comprises comparing a summation of the at least one characteristic of the pulse signals with the at least one threshold.

20. The method of claim 1, wherein:

the at least one pulse signal comprises at least one ultra-wideband pulse; and

the at least one ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

21. An apparatus for erasure detection, comprising

a receiver configured to receive at least one pulse signal;

and

an erasure detector configured to compare at least one characteristic of the at least one pulse signal with at least one threshold, and further configured to designate the at least one pulse signal as at least one erasure based on the comparison.

22. The apparatus of claim 21, wherein the at least one characteristic of the at least one pulse signal relates to at least one of the group consisting of:

signal strength of the at least one pulse signal;

or

amplitude of the at least one pulse signal;

phase of the at least one pulse signal;

frequency of the at least one pulse signal; and

bandwidth of the at least one pulse signal.

23. The apparatus of claim 21, further comprising a threshold generator configured to define the at least one threshold based on at least one characteristic of previously received pulse signals.

24. The apparatus of claim 23, wherein the at least one threshold comprises:

an average of the at least one characteristic of the previously received pulse signals,

a windowed mean of the at least one characteristic of the previously received pulse signals,

a weighted mean of the at least one characteristic of the previously received pulse signals, or

a median of the at least one characteristic of the previously received pulse signals.

25. The apparatus of claim 23, wherein the at least one characteristic of the previously received pulse signals relates to at least one of the group consisting of:

signal strength of the previously received pulse signals;

amplitude of the previously received pulse signals;

phase of the previously received pulse signals;

frequency of the previously received pulse signals; and

bandwidth of the previously received pulse signals.

26. The apparatus of claim 21, further comprising a threshold generator configured to define the at least one threshold based on successful reception of packets.

27. The apparatus of claim 21, further comprising a threshold generator configured to repeatedly adapt the at least one threshold.

28. The apparatus of claim 21, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is greater than or equal to the at least one threshold.

29. The apparatus of claim 21, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is less than or equal to the at least one threshold.

30. The apparatus of claim 21, wherein the comparison is based on:

an infinite impulse response filtered value of the at least one characteristic of the at least one pulse signal;

or

a finite impulse response filtered value of the at least one characteristic of the at least one pulse signal.

31. The apparatus of claim 21, wherein the at least one erasure comprises a Viterbi decision metric for a convolutional code.

32. The apparatus of claim 21, wherein the designation of the received at least one pulse signal as at least one erasure is based on at least one previous comparison of another at least one pulse signal with the at least one threshold.

33. The apparatus of claim 21, wherein the at least one pulse signal comprises at least one pulse position modulated signal.

34. The apparatus of claim 33, wherein the comparison comprises comparing the at least one threshold with energy detected at at least one pulse position defined for the at least one pulse position modulated signal.

35. The apparatus of claim 33, wherein:

the erasure detector is further configured to sum energy levels detected at different pulse positions defined for the at least one pulse position modulated signal; and

the comparison comprises comparing the summed energy levels with the at least one threshold.

36. The apparatus of claim 21, wherein the at least one pulse signal comprises a plurality of pulse signals.

37. The apparatus of claim 36, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is greater than or equal to the at least one threshold.

38. The apparatus of claim 36, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is less than or equal to the at least one threshold.

39. The apparatus of claim 36, wherein the comparison comprises comparing a summation of the at least one characteristic of the pulse signals with the at least one threshold.

40. The apparatus of claim 21, wherein:

the at least one pulse signal comprises at least one ultra-wideband pulse; and

the at least one ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

41. An apparatus for erasure detection, comprising

means for receiving at least one pulse signal;

means for comparing at least one characteristic of the at least one pulse signal with at least one threshold; and

means for designating the at least one pulse signal as at least one erasure based on the comparison.

42. The apparatus of claim 41, wherein the at least one characteristic of the at least one pulse signal relates to at least one of the group consisting of:

signal strength of the at least one pulse signal;

amplitude of the at least one pulse signal;

phase of the at least one pulse signal;

frequency of the at least one pulse signal; and

bandwidth of the at least one pulse signal.

43. The apparatus of claim 41, further comprising means for defining the at least one threshold based on at least one characteristic of previously received pulse signals.

44. The apparatus of claim 43, wherein the at least one threshold comprises:

an average of the at least one characteristic of the previously received pulse signals,

a windowed mean of the at least one characteristic of the previously received pulse signals,

a weighted mean of the at least one characteristic of the previously received pulse signals, or

a median of the at least one characteristic of the previously received pulse signals.

45. The apparatus of claim 43, wherein the at least one characteristic of the previously received pulse signals relates to at least one of the group consisting of:

signal strength of the previously received pulse signals;

amplitude of the previously received pulse signals;

phase of the previously received pulse signals;

frequency of the previously received pulse signals; and

bandwidth of the previously received pulse signals.

46. The apparatus of claim 41, further comprising means for defining the at least one threshold based on successful reception of packets.

47. The apparatus of claim 41, further comprising means for repeatedly adapting the at least one threshold.

48. The apparatus of claim 41, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is greater than or equal to the at least one threshold.

49. The apparatus of claim 41, wherein the comparison comprises determining whether the at least one characteristic of the at least one pulse signal is less than or equal to the at least one threshold.

50. The apparatus of claim 41, wherein the comparison is based on:

an infinite impulse response filtered value of the at least one characteristic of the at least one pulse signal;

or

a finite impulse response filtered value of the at least one characteristic of the at least one pulse signal.

51. The apparatus of claim 41, wherein the at least one erasure comprises a Viterbi decision metric for a convolutional code.

52. The apparatus of claim 41, wherein the designation of the received at least one pulse signal as at least one erasure is based on at least one previous comparison of another at least one pulse signal with the at least one threshold.

53. The apparatus of claim 41, wherein the at least one pulse signal comprises at least one pulse position modulated signal.

54. The apparatus of claim 53, wherein the comparison comprises comparing the at least one threshold with energy detected at at least one pulse position defined for the at least one pulse position modulated signal.

55. The apparatus of claim 53, further comprising:

means for summing energy levels detected at different pulse positions defined for the at least one pulse position modulated signal;

wherein the comparison comprises comparing the summed energy levels with the at least one threshold.

56. The apparatus of claim 41, wherein the at least one pulse signal comprises a plurality of pulse signals.

57. The apparatus of claim 56, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is greater than or equal to the at least one threshold.

58. The apparatus of claim 56, wherein the designation of the pulse signals as at least one erasure is based on whether at least one characteristic of each of the pulse signals is less than or equal to the at least one threshold.

59. The apparatus of claim 56, wherein the comparison comprises comparing a summation of the at least one characteristic of the pulse signals with the at least one threshold.

60. The apparatus of claim 41, wherein:

the at least one pulse signal comprises at least one ultra-wideband pulse; and

the at least one ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

61. A computer-program product for erasure detection, comprising:

computer-readable medium comprising codes executable by at least one computer to;

receive at least one pulse signal;

compare at least one characteristic of the at least one pulse signal with at least one threshold; and

designate the at least one pulse signal as at least one erasure based on the comparison.

62. A headset, comprising:

a receiver configured to receive at least one pulse signal;

an erasure detector configured to compare at least one characteristic of the at least one pulse signal with at least one threshold, and further configured to designate the at least one pulse signal as at least one erasure based on the comparison; and

a transducer configured to provide an audio output based on data received via the receiver.

63. A watch, comprising:

a receiver configured to receive at least one pulse signal;

an erasure detector configured to compare at least one characteristic of the at least one pulse signal with at least one threshold, and further configured to designate the at least one pulse signal as at least one erasure based on the comparison; and

a user interface configured to provide an indication based on data received via the receiver.

64. A sensing device for wireless communication, comprising:

an antenna;

a receiver configured to receive at least one pulse signal via the antenna;

an erasure detector configured to compare at least one characteristic of the at least one pulse signal with at least one threshold, and further configured to designate the at least one pulse signal as at least one erasure based on the comparison; and

a sensor configured to provide data to be transmitted via the antenna.