Robust pulse deinterleaving

• US 7,760,135 B2
• Filed: 11/27/2007
• Issued: 07/20/2010
• Est. Priority Date: 11/27/2007
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Eckenrode, Thomas J., Driggs, Stan W., Twoey, Jerry L., Richter, Walter S.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Barker; Matthew M
• Application Number:
  US11/986,899
• Publication Number:
  US 20090135052A1
• Time in Patent Office: 966 Days
• Field of Search: 342/195, 342/90
• US Class Current: 342/195
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals

Abstract

Systems and methods are presented for associating time slices of a received signal with previously encountered time slices. A parameter determination component determines at least one parameter for each received time slice. A content addressable memory stores a plurality of parameter values associated with the previously encountered time slices. The content addressable memory is searchable such that the determined at least one parameter for each received time slice can be compared to the stored plurality of parameter values to provide a memory output. An emitter matching component associates a given received time slice with one of a plurality of emitters according to the memory output.

Claims

1. A deinterleaving system that associates time slices of a received signal with previously encountered time slices, comprising:

a parameter determination component that determines at least one parameter for each received time slice;

a ternary content addressable memory that stores a plurality of parameter values associated with the previously encountered time slices, the content addressable memory being searchable such that the determined at least one parameter for each received time slice can be compared to the stored plurality of parameter values to provide a memory output, the stored plurality of parameter values comprising a first parameter value having at least one “

don'"'"'t care”

bit as at least one least significant bit as to represent a first range of values, and a second parameter value representing a smaller range of values that is subsumed by the first range of values, the first parameter value and the second parameter value representing the same emitter; and

an emitter matching component that associates a given received time slice with one of a plurality of emitters according to the memory output.

2. The system of claim 1, the parameter determination component comprising a pulse width determination component that determines an associated pulse width of each received time slice.

3. The system of claim 1, further comprising a spectral analysis component that determines at least one frequency characteristic of the received signal via a fast Fourier transform.

4. The system of claim 1, further comprising an emitter characterization element that calculates at least one characteristic of an emitter from a plurality of time slices associated with the emitter by the emitter matching component.

5. The system of claim 1, the determined at least one parameter comprising a first parameter and a second parameter, and the content addressable memory comprising a first content addressable memory that stores parameter values associated with the first parameter and a second content addressable memory that stores parameter values associated with the second parameter.

6. The system of claim 1, the emitter matching component comprising a rule-based classifier.

7. A radar detection system, comprising:

at least one radio frequency receiver that receives an radio frequency signal and conditions the received signal to provide a plurality of time slices for analysis; and

the deinterleaving system of claim 1.

8. A method for determining at least one characteristic of an emitter, comprising:

conditioning a received signal to identify a plurality of time slices;

determining at least one parameter of each of the plurality of time slices;

conducting an imprecise search of a memory for the determined at least one parameter, such that the determined at least one parameter is compared to a first stored string of ternary bits, representing a first range of values, and a second stored string of ternary bits, representing a second range of values smaller than the first range of values to produce a memory output;

associating each time slice with one of a plurality of emitters according to the memory output; and

determining the at least one characteristic of the emitter from a plurality of time slices associated with the emitter.

9. The method of claim 8, wherein conducting the imprecise search of the memory comprises searching a ternary content addressable memory that is configured to be searched in one processing cycle.

10. The method of claim 8, wherein the first range of values and the second range of values both represent a first emitter, and the first range of values encompasses the second range of values.

11. The method of claim 8, wherein the plurality of time slices represent signal pulses and the determined at least one parameter comprises a pulse width.

12. The method of claim 8, wherein conditioning the received signal comprises calculating a fast Fourier transform of the received signal.

13. A radar detection system, comprising:

at least one radio frequency receiver that receives an radio frequency signal and conditions the received signal to provide a plurality of signal pulses for analysis;

a parameter determination component that determines at least one parameter for each received signal pulse; and

a ternary content addressable memory that stores a plurality of parameter values associated with previously encountered signal pulses, the ternary content addressable memory being searchable such that the determined at least one parameter for each received signal pulse can be compared to the stored plurality of parameter values to provide a memory output, the stored plurality of parameter values comprising a first parameter value having at least one “

don'"'"'t care”

bit as at least one least significant bit as to represent a first range of values, and a second parameter value representing a smaller range of values that is subsumed by the first range of values, the first parameter value and the second parameter value each representing a first emitter.

14. The system of claim 13, further comprising an emitter matching component that associates a given signal pulse with one of a plurality of emitters according to the memory output.

15. The system of claim 14, further comprising an emitter characterization element that calculates at least one characteristic of an emitter from a plurality of signal pulses associated with the emitter by the emitter matching component.

16. The system of claim 13, the determined at least one parameter comprising a first parameter and a second parameter, and the ternary content addressable memory comprising a first content addressable memory that stores parameter values associated with the first parameter and a second content addressable memory that stores parameter values associated with the second parameter.

17. The system of claim 13, the parameter determination component comprising a pulse width determination component that determines an associated pulse width of each signal pulse.