Method and apparatus for acquiring wide-band pseudorandom noise encoded waveforms

• US 6,362,760 B2
• Filed: 12/04/2000
• Issued: 03/26/2002
• Est. Priority Date: 08/21/1997
• Status: Expired due to Term

• Current Assignee: Data Fusion Corp.
• Original Assignee: Data Fusion Corp.
• Inventors: Thomas, John K., Kober, Wolfgang
• Primary Examiner(s): WAMSLEY, PATRICK G
• Application Number:
  US09/730,330
• Publication Number:
  US 20010000216A1
• Time in Patent Office: 477 Days
• Field of Search: 341/118, 341/120, 341/50, 341/141, 341/61, 704/200, 704/229, 704/203, 704/230, 365/45, 380/36, 375/240, 381/2
• US Class Current: 341/141
• CPC Class Codes: G01S 1/045 Receivers
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: H03M 1/121 Interleaved, i.e. using multiple converters or converter parts for one channel

Abstract

The method and apparatus of the present invention is directed to architectures for signal processing, such as for performing analog-to-digital and digital-to-analog conversions, in which the source signal is decomposed into subband signals by an analysis filter, processed, and the processed subband signals combined to form a reconstructed signal that is representative of the source signal.

Claims

1. A method for transmitting a signal, comprising:

decomposing a signal having a signal bandwidth into at least first and second sub-band signals, each of the first and second sub-band signals having a respective sub-band signal bandwidth included within the signal bandwidth;

transmitting each of the first and second sub-band signals;

receiving each of the first and second sub-band signals; and

combining each of the received first and second sub-band signals to form a composite signal.

2. The method of claim 1, wherein the transmitting step comprises:

encoding the first and second sub-band signals; and

wherein the receiving step comprises;

decoding the received first and second sub-band signals.

3. The method of claim 2 wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

4. The method of claim 1, wherein the decomposing step comprises:

passing the signal through an analysis filter, and

wherein the combining step comprises;

passing each of the first and second sub-band signals through a synthesis filter.

5. The method of claim 1, wherein the transmitting step comprises:

emitting the at least first and second sub-band signals from a corresponding plurality of signal sources; and

wherein the receiving step comprises;

receiving the transmitted at least first and second sub-band signals with a corresponding plurality of signal receptors.

6. The method of claim 1, further comprising:

converting the first and second sub-band signals from a digital form to an analog form.

7. The method of claim 1, further comprising, before the combining step:

converting the received first and second sub-band signals from a radio frequency to a baseband frequency; and

converting the baseband frequency first and second sub-band signals from an analog format to a digital format.

8. The method of claim 1, wherein the receiving step comprises:

correlating the received first and second sub-band signals with a replica of the transmitted first and second sub-band signals.

9. The method of claim 1, wherein the receiving step comprises:

determining whether a respective noise component of the first and second sub-band signals is above a signal level; and

when a noise component is above the signal level, rejecting the corresponding sub-band signal.

10. A system for transmitting a signal, comprising:

means for decomposing a signal having a signal bandwidth into at least first and second sub-band signals, each of the first and second sub-band signals having a respective sub-band signal bandwidth included within the signal bandwidth;

means for transmitting each of the first and second sub-band signals;

means for receiving each of the first and second sub-band signals; and

means for combining each of the received first and second sub-band signals to form a composite signal.

11. The system of claim 10, wherein the decomposing means comprises:

an analysis filter and wherein the combining means comprises a synthesis filter.

12. The system of claim 11, wherein the analysis and synthesis filters are perfect reconstruction filters.

13. The system of claim 10, wherein the transmitting means comprises encoding means for encoding, prior to transmission, the first and second sub-band signals and wherein the receiving means comprises decoding means for decoding the received first and second sub-band signals.

14. The system of claim 13 wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

15. The system of claim 10, wherein the transmitting means comprises a plurality of signal sources corresponding to the at least a first and second sub-band signals and wherein the receiving means comprises a plurality of signal receptors corresponding to the received at least first and second sub-band signals.

16. The system of claim 10, further comprising:

converting means for converting the first and second sub-band signals from one of analog to digital or from digital to analog.

17. The system of claim 10, further comprising:

down converting means for converting the received first and second sub-band signals from a radio frequency to a baseband frequency; and

analog-to-digital converting means for converting the baseband frequency first and second sub-band signals from an analog format to a digital format.

18. The system of claim 10, wherein the receiving means comprises:

correlating means for correlating the received first and second sub-band signals with a replica of the transmitted first and second sub-band signals.

19. The system of claim 10, wherein the receiving means comprises:

means for determining whether a respective noise component of the first and second sub-band signals is above a selected level; and

means for rejecting at least one of the first or second sub-band signal when the respective noise component is above the selected level.

20. A system for signal transmission, comprising:

at least one analysis filter operable to decompose a signal having a signal bandwidth into at least first and second sub-band signals, each of the first and second sub-band signals having a respective sub-band signal bandwidth included within the signal bandwidth; and

at least one transmitter operable to transmit independently each of the first and second sub-band signals.

21. The system of claim 20, further comprising:

at least one signal receptor operable to receive each of the first and second sub-band signals; and

at least one synthesis filter operable to combine each of the received first and second sub-band signals to form a composite signal.

22. The system of claim 21, further comprising:

at least one encoder operable to encode, before transmission, the first and second sub-band signals; and

at least one decoder operable to decode the received first and second sub-band signals.

23. The system of claim 22 wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

24. The system of claim 21, further comprising:

a down converter operable to convert the received first and second sub-band signals from a radio frequency to a baseband frequency; and

an analog-to-digital converter operable to convert the baseband frequency first and second sub-band signals from an analog format to a digital format.

25. The system of claim 21, further comprising:

a correlator operable to correlate the received first and second sub-band signals with a replica of the transmitted first and second sub-band signals.

26. The system of claim 21, further comprising:

a noise reducing quantizer that, in a first mode, is operable to determine whether a respective noise component of the first and second sub-band signals is above a signal level and, in a second mode, is operable to reject the corresponding sub-band signal when a noise component is above the signal level.

27. The system of claim 20, wherein the first and second sub-band signals are digital and further comprising:

a digital-to-analog converter operable to convert the first and second sub-band signals to an analog format.

28. A method for transmitting a signal, comprising:

decomposing a signal having a signal bandwidth into at least first and second sub-band signals, each of the first and second sub-band signals having a respective sub-band signal bandwidth included within the signal bandwidth and

transmitting separately each of the first and second sub-band signals.

29. The method of claim 28, further comprising:

receiving each of the first and second sub-band signals; and

combining each of the first and second sub-band signals to form a composite signal.

30. The method of claim 29, wherein the transmitting step comprises:

encoding the first and second sub-band signals; and

wherein the receiving step comprises;

decoding the received first and second sub-band signals.

31. The method of claim 30, wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

32. The method of claim 29, wherein the transmitting step comprises:

emitting the at least a first and second sub-band signals from a corresponding plurality of signal sources; and

wherein the receiving step comprises;

receiving the transmitted at least a first and second sub-band signals with a corresponding plurality of signal receptors.

33. The method of claim 29, further comprising:

converting the first and second sub-band signals from an analog format to a digital format.

34. The method of claim 29, further comprising, before the combining step:

converting the received first and second sub-band signals from a radio frequency to a baseband frequency; and

converting the baseband frequency first and second sub-band signals from an analog format to a digital format.

35. The method of claim 29, wherein the receiving step comprises:

determining whether a respective noise component of the first and second sub-band signals is above a selected level; and

when a noise component is above the selected level, rejecting the corresponding sub-band signal.

36. A method for receiving transmitted first and second sub-band signals, the transmitted first and second sub-band signals having respective first and second sub-band signal bandwidths and being components of a signal having a signal bandwidth that includes the first and second signal bandwidths, comprising:

receiving independently each of the first and second sub-band signals; and

combining each of the first and second sub-band signals to form a composite signal.

37. The method of claim 36, further comprising:

decomposing the signal into the first and second sub-band signals; and

transmitting the first and second sub-band signals.

38. The method of claim 37, wherein the decomposing step comprises:

passing the signal through an analysis filter; and

wherein the combining step comprises;

passing each of the first and second sub-band signals through a synthesis filter.

39. The method of claim 37, wherein the transmitting step comprises:

emitting the at least a first and second sub-band signals from a corresponding plurality of signal sources; and

wherein the receiving step comprises;

receiving the transmitted at least a first and second sub-band signals with a corresponding plurality of signal receptors.

40. The method of claim 37, further comprising:

converting the first and second sub-band signal segments from digital to analog.

41. The method of claim 37, further comprising, before the combining step:

converting the received first and second sub-band signals from a radio frequency to a baseband frequency; and

converting the baseband frequency first and second sub-band signals from an analog format to a digital format.

42. The method of claim 37, wherein the transmitting step comprises:

encoding the first and second sub-band signals; and

wherein the receiving step comprises;

decoding the received first and second sub-band signals.

43. The method of claim 37 wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

44. The method of claim 37, wherein the receiving step comprises:

correlating the received first and second sub-band signals with a replica of the transmitted first and second sub-band signals.

45. The method of claim 37, wherein the receiving step comprises:

determining whether a respective noise component of the first and second sub-band signals is above a selected level; and

when a noise component is above the selected level rejecting the corresponding sub-band signal.

46. A system for receiving transmitted first and second sub-band signals, the transmitted first and second sub-band signals having respective first and second sub-band signal bandwidths and being components of a signal having a signal bandwidth that includes the first and second signal bandwidths, comprising:

at least one signal receptor operable to receive separately each of the first and second sub-band signals; and

at least one synthesis filter operable to combine each of the first and second sub-band signals to form a composite signal.

47. The method of claim 46, further comprising:

at least one analysis filter operable to decompose the signal into the first and second sub-band signals; and

at least signal emitter operable to transmit the first and second sub-band signals.

48. The system of claim 47, further comprising:

a plurality of encoders operable to encode the first and second sub-band signals; and

a plurality of decoders operable to decode the received first and second sub-band signals.

49. The system of claim 48 wherein the first and second sub-band signals are encoded simultaneously and the received first and second sub-band signals are decoded simultaneously.

50. The system of claim 47, wherein the at least one signal emitter comprises a plurality of transmitters and the at least one signal receptor comprises a plurality of antennas.

51. The system of claim 47, further comprising:

a plurality of digital-to-analog converters operable to convert the first and second sub-band signals from digital to analog.

52. The system of claim 47, further comprising:

a plurality of down converters operable to convert the received first and second sub-band signals from a radio frequency to a baseband frequency; and

a plurality of analog-to-digital converters operable to convert the baseband frequency first and second sub-band signals from an analog format to a digital format.

53. The system of claim 47, further comprising:

a plurality of correlators operable to correlate the received first and second sub-band signals with a replica of the transmitted first and second sub-band signals.

54. The system of claim 47, further comprising:

a noise reducing quantizer operable in a first mode to determine a respective noise component of a sub-band signal is above a selected level and in a second mode to reject the sub-band signal when the respective noise component of the sub-band signal is above the selected level.