CALIBRATION SYSTEM AND METHOD

• US 20120027063A1
• Filed: 12/22/2010
• Published: 02/02/2012
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Wertz, Daniel S., Patel, Kunal H., Corley, Charles L. II
• Granted Patent: US 8,514,978 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/364 Delay profiles
• CPC Class Codes: H04L 2025/03598 Algorithms

Abstract

Receiving a modulated carrier signal that is modulated using a reference signal, wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer. Further including routing the modulated carrier signal through a receiver system to generate a processed signal, receiving the processed signal at the digitizer, digitizing the processed signal at the digitizer, and determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

Claims

1. A method comprising:

receiving, at a receiver system, a modulated carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

2. The method of claim 1, wherein the receiver system comprises an onboard signal source, and further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

3. The method of claim 1, wherein the reference signal is generated by the digitizer.

4. The method of claim 1, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

5. The method of claim 1, further comprising modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that receiving, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

6. The method of claim 5, further comprising determining delay vs. frequency data based on the determined delay, and generating an equalization filter based on the delay vs. frequency data.

7. The method of claim 6, further comprising:

receiving a radio-frequency (RF) signal from a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

8. The method of claim 1, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

9. The method of claim 8, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

10. A system, comprising:

a receiver system configured to;

receive a modulated a carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer; and

route the modulated carrier signal through the receiver system to generate a processed signal; and

the digitizer, configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

11. The system of claim 10, wherein the receiver system comprises an onboard signal source and wherein the receiver system is configured to generate the modulated carrier signal by modulating a signal provided from the onboard signal source.

12. The system of claim 10, wherein the digitizer is configured to generate the reference signal.

13. The system of claim 10, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

14. The system of claim 10, wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of the downconverter such that modulating, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across the analysis bandwidth of the downconverter.

15. The system of claim 14, wherein the determined delays are used to determine delay vs. frequency data, and wherein the system is configured to generate an equalization filter based on the delay vs. frequency data.

16. The system of claim 15,

wherein the receiver system is further configured to:

receive a radio-frequency (RF) signal form a source external to the receiver system;

route the RF signal through the receiver system to generate a processed RF signal; and

wherein the digitizer is further configured to;

receive the processed RF signal at the digitizer; and

digitize the processed RF signal, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system.

17. The system of claim 10, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

18. The method of claim 17, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

19. A computer readable storage medium comprising program instruction stored thereon, wherein the program instructions are executable by a computer to cause:

receiving, at a receiver system, a modulated carrier signal wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

20. The computer readable storage medium of claim 19, wherein the receiver system comprises an onboard signal source, and further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

21. The computer readable storage medium of claim 19, wherein the reference signal is generated by the digitizer.

22. The computer readable storage medium of claim 19, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

23. The computer readable storage medium of claim 19, further comprising modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that execution of the instructions causes the receiving, routing, receiving, digitizing and determining a delay to be repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

24. The computer readable storage medium of claim 23, wherein execution of the instructions causes generation of delay vs. frequency data based on the determined delay, and generation of an equalization filter based on the delay vs. frequency data.

25. The computer readable storage medium of claim 24, further comprising:

receiving a radio-frequency (RF) signal form a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

26. The computer readable storage medium of claim 19, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

27. The computer readable storage medium of claim 26, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

28. A system, comprising:

a downconverter receiver system configured to;

modulate a carrier signal generated from an onboard signal source of the downconverter receiver system, wherein the carrier signal is modulated using a reference signal provided from a digitizer such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer; and

route the modulated carrier signal through a receiver device of the downconverter receiver system to generate a processed signal;

wherein the digitizer is configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the downconverter receiver system based on the timing of the processed signal.

29. A system, comprising:

a digitizer configured to;

provide a reference signal to a downconverter receiver system, wherein the downconverter receiver system is configured to;

modulate a carrier signal generated from an onboard signal source of the downconverter receiver system, wherein the carrier signal is modulated using the reference signal provided from the digitizer such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer; and

route the modulated carrier signal through a receiver device of the downconverter receiver system to generate a processed signal;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the downconverter receiver system based on the timing of the processed signal.