Methods and systems for detecting repetitive synchronized signal events

• US 20090003422A1
• Filed: 06/27/2007
• Published: 01/01/2009
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Ha, Stephen T.
• Granted Patent: US 8,433,739 B2
• Time in Patent Office: Days
• US Class Current: 375/225
• CPC Class Codes: H04B 14/006 Angle modulation

Abstract

Repetitive synchronized signal events may be detected in received raw signal data that contains a signal. The type of signal, element length (or minimum interval) and/or other characteristics of such repetitive synchronized signal events may also be optionally determined. The disclosed methods and systems may be implemented for processing signals in real time as part of a receiver or transceiver system, or may be implemented by one or more computer processing components that are configured to process stored raw signal data or signal data received from another source, such as across a computer network.

Claims

1. A method of processing signal data, comprising:

receiving said signal data;

obtaining reinforceable repetitive synchronous data from said signal data;

obtaining time-time data from said reinforceable repetitive synchronous data, said time-time data comprising multiple data traces;

adding said time-time data in phase across said multiple data traces to obtain a sum of said time-time data; and

outputting said sum of said time-time data for at least one of display, storage, or further processing.

2. The method of claim 1, wherein said reinforceable repetitive synchronous data comprises rectified average delta data.

3. The method of claim 1, further comprising identifying a high amplitude event in said sum of said time-time data, and determining the presence of a repetitive synchronous event in said signal data from said high amplitude event.

4. The method of claim 1, further comprising identifying a pattern within said sum of said time-time data, and determining one or more characteristics of said signal data.

5. The method of claim 1, further comprising providing an initial estimate of element length of a repetitive synchronous event in said signal data;

then orienting said multiple data traces of said time-time data relative to each other based on said estimated element length prior to adding said time-time data in phase across said multiple data traces; and

then determining a revised estimate of said element length based on said sum of said time-time data.

6. The method of claim 5, further comprising obtaining an amplitude spectrum of said reinforceable repetitive synchronous data;

and then providing said initial estimate of element length of said repetitive synchronous event from said amplitude spectrum of said reinforceable repetitive synchronous data.

7. The method of claim 6, further comprising applying a Fast Fourier Transform to said reinforceable repetitive synchronous data to obtain said amplitude spectrum;

and adding said time-time data in phase across said multiple data traces to obtain a Radon sum of said time-time data.

8. The method of claim 1, said method comprising:

receiving a dwell of said signal data;

obtaining reinforceable repetitive synchronous data from said I-Q data of said dwell of said signal data;

obtaining time-time data from said reinforceable repetitive synchronous data corresponding to said dwell of said signal data, said time-time data comprising multiple data traces; and

adding said time-time data in phase across said multiple data traces to obtain a sum of said time-time data corresponding to said dwell of said signal data.

9. The method of claim 1, said method comprising:

receiving multiple dwells of said signal data;

obtaining reinforceable repetitive synchronous data from said I-Q data of each of said multiple dwells of said signal data;

adding said reinforceable repetitive synchronous data corresponding to said multiple dwells of said signal data to obtain a sum of reinforceable repetitive synchronous data;

obtaining time-time data from said sum of reinforceable repetitive synchronous data, said time-time data comprising multiple data traces; and

adding said time-time data in phase from said sum of reinforceable repetitive synchronous data across said multiple data traces to obtain a sum of said time-time data corresponding to said multiple dwells of said signal data.

10. A method of detecting repetitive synchronized signal events, said method comprising detecting the presence of a repetitive synchronized signal event in signal data from an in-phase sum of reinforceable repetitive synchronous data across multiple traces obtained from said signal data.

11. The method of claim 10, wherein said reinforceable repetitive synchronous data comprises rectified average delta data.

12. The method of claim 10, wherein said signal data comprises raw signal data that includes at least one signal, said repetitive synchronized signal event corresponding to said at least one signal.

13. The method of claim 12, wherein said signal comprises a phase-shift key (PSK) signal and said repetitive synchronized signal event comprises a phase transition in said PSK signal;

or wherein said signal comprises a frequency modulated continuous wave (FMCW) signal and said repetitive synchronized signal event comprises a frequency slope change in said FMCW signal;

or wherein said signal comprises a frequency-shift key (FSK) signal and said repetitive synchronized signal event comprises a frequency transition in said FSK signal.

14. The method of claim 12, wherein said repetitive synchronized signal event comprises an envelope in the said signal encoding a fixed periodic data pattern.

15. The method of claim 12, wherein said signal comprises a radar signal.

16. The method of claim 12, further comprising determining the signal type of said signal based on said in-phase sum of reinforceable repetitive synchronous data obtained from said signal data.

17. The method of claim 16, wherein said signal comprises a PSK signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from delta phase data obtained from the unwrapped phase of I-Q data of said signal data;

or wherein said signal comprises a FSK signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from a differentiation of delta phase data obtained from the unwrapped phase of I-Q data of said signal data;

or wherein said signal comprises a FMCW signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from a double differentiation of delta phase data obtained from the unwrapped phase of I-Q data of said signal data.

18. The method of claim 16, wherein said signal comprises a FSK signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from a level change detection of the envelope obtained from the differentiated I and Q data of said signal data;

or wherein said signal comprises a FMCW signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from a frequency peak detection of the envelope obtained from the differentiated I and Q data of said signal data.

19. The method of claim 16, wherein said signal comprises a PSK signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from the envelope of the unwrapped phase of I and Q data of said signal data encoding a fixed periodic data pattern;

or wherein said signal comprises a FSK signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from the envelope obtained from the differentiated I and Q data of said signal data encoding a fixed periodic data pattern;

or wherein said signal comprises a FMCW signal and wherein said in-phase sum of reinforceable repetitive synchronous data is obtained from the envelope obtained from the differentiated I and Q data of said signal data encoding a fixed periodic data pattern.

20. The method of claim 10, further comprising determining a minimum element length of said repetitive synchronous event based on said in-phase sum of reinforceable repetitive synchronous data obtained from said signal data.

21. The method of claim 10, further comprising receiving said signal data;

and performing said step of detecting the presence of said repetitive synchronized signal event in real time as said signal data is received.

22. A system for processing signal data, comprising one or more system components configured to:

receive said signal data;

obtain reinforceable repetitive synchronous data from said I-Q data;

obtain time-time data from said reinforceable repetitive synchronous data, said time-time data comprising multiple data traces; and

add said time-time data in phase across said multiple data traces to obtain a sum of said time-time data.

23. The system of claim 22, wherein said reinforceable repetitive synchronous data comprises rectified average delta data.

24. The system of claim 22, wherein said one or more system components are further configured to identify a high amplitude event in said sum of said time-time data, and to determine the presence of a repetitive synchronous event in said signal data from said high amplitude event.

25. The system of claim 22, wherein said one or more system components are further configured to identify a pattern in said sum of said time-time data, and to determine one or more characteristics of said signal data.

26. The system of claim 22, wherein said one or more system components are further configured to:

provide an initial estimate of element length of a repetitive synchronous event in said signal data;

then orient said multiple data traces of said time-time data relative to each other based on said estimated element length prior to adding said time-time data in phase across said multiple data traces; and

then determine a revised estimate of said element length based on said sum of said time-time data.

27. The system of claim 26, wherein said one or more system components are further configured to obtain an amplitude spectrum of said reinforceable repetitive synchronous data;

and then to provide said initial estimate of element length of said repetitive synchronous event from said amplitude spectrum of said reinforceable repetitive synchronous data.

28. The system of claim 27, wherein said one or more system components are further configured to apply a Fast Fourier Transform to said reinforceable repetitive synchronous data to obtain said amplitude spectrum;

and to add in phase data across said multiple data traces to obtain a Radon sum of said time-time data.

29. The system of claim 22, wherein said one or more system components are further configured to:

receive a dwell of said signal data;

obtain reinforceable repetitive synchronous data from said I-Q data of said dwell of said signal data;

obtain time-time data from said reinforceable repetitive synchronous data corresponding to said dwell of said signal data, said time-time data comprising multiple data traces; and

add said time-time data in phase across said multiple data traces to obtain a sum of said time-time data corresponding to said dwell of said signal data.

30. The system of claim 22, wherein said one or more system components are further configured to:

receive multiple dwells of said signal data;

obtain reinforceable repetitive synchronous data from said I-Q data of each of said multiple dwells of said signal data;

add said reinforceable repetitive synchronous data corresponding to said multiple dwells of said signal data to obtain a sum of reinforceable repetitive synchronous data;

obtain time-time data from said sum of reinforceable repetitive synchronous data, said time-time data comprising multiple data traces; and

add said time-time data from said sum of reinforceable repetitive synchronous data in phase across said multiple data traces to obtain a sum of said time-time data corresponding to said multiple dwells of said signal data.

31. A system for detecting repetitive synchronized signal events, said system comprising:

an event detector, said event detector being configured to receive signal data and obtain an in-phase sum of reinforceable repetitive synchronous data from said signal data; and

wherein said event detector is further configured to detect the presence of a repetitive synchronized signal event in said signal data from said in-phase sum of reinforceable repetitive synchronous data obtained from said signal data.

32. The method of claim 31, wherein said reinforceable repetitive synchronous data comprises rectified average delta data.

33. The system of claim 31, wherein said signal data comprises raw signal data that includes at least one signal;

wherein said repetitive synchronized signal event corresponds to said at least one signal; and

wherein said system further comprises receive path circuitry coupled to receive said raw signal data from at least one antenna, said receive path circuitry being coupled between said antenna and said event detector.

34. The system of claim 33, wherein said signal comprises a phase-shift key (PSK) signal and said repetitive synchronized signal event comprises a phase transition in said PSK signal;

or wherein said signal comprises a frequency modulated continuous wave (FMCW) signal and said repetitive synchronized signal event comprises a frequency slope change in said FMCW signal;

or wherein said signal comprises a frequency-shift key (FSK) signal and said repetitive synchronized signal event comprises a frequency transition in said FSK signal.

35. The system of claim 33, wherein said repetitive synchronized signal event comprises an envelope in the said signal encoding a fixed periodic data pattern.

36. The method of claim 33, wherein said signal comprises a radar signal.

37. The system of claim 31, wherein said event detector is further configure to determine the signal type of said signal based on said in-phase sum of reinforceable repetitive synchronous data obtained from said signal data.

38. The system of claim 37, wherein said signal comprises a PSK signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from delta phase data obtained from the unwrapped phase of I-Q data of said signal data;

or wherein said signal comprises a FSK signal and wherein event detector is configured to obtain said in-phase sum of reinforceable repetitive synchronous data from a differentiation of delta phase data obtained from the unwrapped phase of I-Q data of said signal data;

or wherein said signal comprises a FMCW signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from a double differentiation of delta phase data obtained from the unwrapped phase of I-Q data of said signal data.

39. The system of claim 37, wherein said signal comprises a FSK signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from a level change detection of the envelope obtained from the differentiated I and Q data of said signal data;

or wherein said signal comprises a FMCW signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from a frequency peak detection of the envelope obtained from the differentiated I and Q data of said signal data.

40. The system of claim 37, wherein said signal comprises a PSK signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from the envelope of the unwrapped phase of I and Q data of said signal data encoding a fixed periodic data pattern;

or wherein said signal comprises a FSK signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from the envelope obtained from the differentiated I and Q data of said signal data encoding a fixed periodic data pattern;

or wherein said signal comprises a FMCW signal and wherein said event detector is configured to obtain an in-phase sum of reinforceable repetitive synchronous data from the envelope obtained from the differentiated I and Q data of said signal data encoding a fixed periodic data pattern.

41. The system of claim 31, wherein said event detector is further configured to determine a minimum element length of said repetitive synchronous event based on said in-phase sum of reinforceable repetitive synchronous data obtained from said signal data.

42. The system of claim 31, wherein said event detector is further configured to receive said signal data and to detect the presence of said repetitive synchronized signal event in real time as said signal data is received.