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

• US 6,252,535 B1
• Filed: 08/20/1998
• Issued: 06/26/2001
• 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:
  US09/137,383
• Time in Patent Office: 1,041 Days
• Field of Search: 341/155, 341/126, 341/144, 704/220, 704/219, 704/203, 704/229
• US Class Current: 341/155
• 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 acquiring a signal having a bandwidth, comprising:

decomposing the signal into n signal segments, each signal segment having a signal segment bandwidth that is less than the signal bandwidth;

processing y of the n signal segments to form a plurality of processed signal segments, wherein y is less than n; and

combining the processed signal segments into a composite signal wherein the signal is one of analog or digital and the composite signal is the other one of analog or digital.

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

correlating the plurality of y signal segments with a corresponding plurality of replicated signal segments to provide a corresponding plurality of correlation functions.

3. The method of claim 2, wherein the processing step comprises:

determining an amplitude, time delay, and phase delay for at least a portion of a plurality of peaks defined by the plurality of correlation functions and

realigning and scaling at least a portion of the signal defined by the signal segments based on one or more of the amplitude, time delay, and phase delay for the at least a portion of the plurality of peaks.

4. The method of claim 1, wherein the processing step includes performing analog-to-digital conversion of each of the y signal segments.

5. The method of claim 1, wherein the processing step includes performing digital-to-analog conversion of each of the y signal segments.

6. The method of claim 1, wherein the processing step includes removing a noise component from each of the y signal segments to form a corresponding plurality of noise reduced signal segments and thereafter converting each of the noise reduced signal segments from one of analog or digital format to the other of analog or digital format.

7. The method of claim 1, wherein in the processing step each of the y signal segments is processed separately.

8. The method of claim 1, wherein the composite signal has the same bandwidth as the signal bandwidth.

9. The method of claim 1, wherein the composite signal is a time delayed replica of the signal.

10. The method of claim 1, wherein the signal has a bandwidth of at least about 1 GHz.

11. The method of claim 1, wherein the sum of the plurality of signal segment bandwidths is equivalent to the signal bandwidth.

12. The method of claim 1, wherein the signal is in one of analog or digital format and the composite signal is in the other of analog or digital format.

13. The method of claim 1, wherein the processing step comprises:

assigning boundary values to a plurality of bins;

sampling a signal segment to provide a sampled value corresponding to the sampled portion of the signal segment;

comparing the sampled value with assigned boundary values for each of the plurality of bins;

selecting an appropriate bin for the sampled portion of the signal segment;

thereafter reassigning new boundary values to at least a portion of the plurality of bins; and

repeating the assigning, sampling, comparing and selecting steps.

14. The method of claim 1, wherein the processing step includes the step of:

eliminating any of the n signal segments having a signal-to-noise ratio of less than one to form the y signal segments.

15. The method of claim 1 wherein n-y of the signal segments are not processed in the processing step.

16. An apparatus for acquiring a signal having a signal bandwidth, comprising:

means for receiving a signal in the form of a pseudorandom or random waveform having a signal bandwidth;

means for decomposing the signal into n signal segments, each signal segment having a signal segment bandwidth that is less than the signal bandwidth;

means for processing y of the signal segments to form a plurality of processed signal segments, wherein y is less than n; and

means for combining the processed signal segments into a composite signal wherein the signal is one of analog or digital and the composite signal is the other one of analog or digital.

17. The apparatus of claim 16, wherein the means for processing includes means for performing analog-to-digital conversion of each of the y signal segments.

18. The apparatus of claim 16, wherein the means for processing includes means for performing digital-to-analog conversion of each of the signal segments.

19. The apparatus of claim 16, wherein the means for decomposing is a plurality of low pass filters.

20. The apparatus of claim 16, wherein the means for decomposing includes a plurality of analysis filters and the means for combining includes a plurality of synthesis filters.

21. The apparatus of claim 16, wherein the means for combining is a perfect reconstruction filter bank.

22. The apparatus of claim 16, wherein the means for processing includes at least one of a plurality of analog-to-digital converters and a plurality of digital-to-analog converters.

23. The apparatus of claim 16, wherein the means for processing includes a noise rejecting quantizer.

24. The apparatus of claim 16, wherein the processing means includes means for rejecting any of the n signal segments having a signal-to-noise ratio of less than one to form the y signal segments.

25. The apparatus wherein n-y of the signal segments are not processed by the processing means.

26. A method for forming a composite signal having a composite bandwidth from a first plurality of signal segments, the frequency band of the composite signal including each of the signal segments, the method comprising:

eliminating from the first plurality of signal segments any signal segment in which a noise component exceeds a signal component to form a second plurality of signal segments, the second plurality of signal segments being less than the first plurality of signal segments; and

performing synthesis filtering on each of the second plurality of signal segments to form the composite signal.

27. The method of claim 26, further comprising:

emitting the first plurality of signal segments from a plurality of signal sources and

receiving each of the first plurality of signal segments using a corresponding plurality of signal receptors.

28. The method of claim 26, further comprising:

converting each of the second plurality of signal segments from an analog format to a digital format.

29. A system for forming a composite signal having a composite bandwidth from a first plurality of signal segments, the composite bandwidth including the frequency range of each of the signal segments, the system comprising:

means for rejecting any of the first plurality of signal segments in which a noise component exceeds a signal component to form a second plurality of signal segments; and

means for performing synthesis filtering on each of the second plurality of signal segments to form the composite signal.

30. The system of claim 29, further comprising:

means for emitting the first plurality of signal segments and

means for receiving each of the first plurality of signal segments.

31. The system of claim 29, further comprising:

means for converting each of the second plurality of signal segments from an analog format to a digital format.

32. The system of claim 29, further comprising:

a plurality of analysis filters to decompose a source signal into the first plurality of signal segments;

a plurality of digital-to-analog conversion devices for converting the second plurality of decomposed signal segments from digital into analog format to form a corresponding plurality of analog signal segments;

a plurality of amplifiers to form a corresponding plurality of amplified analog signal segments;

a plurality of signal emitters for emitting the plurality of amplified analog signal segments; and

a plurality of receptors for receiving, from the plurality of signal emitters, the plurality of amplified analog signal segments.

33. The system of claim 29, further comprising:

a plurality of analysis filters to decompose a source signal into the first plurality of signal segments;

a plurality of amplifiers to amplify the second plurality of signal segments to form a corresponding plurality of amplified signal segments;

a plurality of signal emitters for emitting the plurality of amplified signal segments; and

a plurality of receptors for receiving the plurality of amplified signal segments.

34. The system of claim 29, further comprising:

a plurality of receptors for receiving the first plurality of signal segments;

a plurality of analog-to-digital converters to convert the second plurality of signal segments into a plurality of digital signal segments.

35. The system of claim 29, wherein the number of the first plurality of signal segments is more than the number of the second plurality of signal segments.

36. A method for processing an analog signal having a bandwidth, comprising:

decomposing the analog signal into a first plurality of analog signal segments, each analog signal segment having a signal segment bandwidth that is less than the signal bandwidth;

rejecting any of the analog signal segments in which the signal-to-noise ratio is less than one to form a second plurality of analog signal segments; and

processing each of the second plurality of analog signal segments to form a plurality of processed analog signal segments; and

combining the processed analog signal segments into a composite signal.

37. The method of claim 36, wherein the number of the first plurality of signal segments is more than the number of the second plurality of signal segments.