PRIME-BASED FREQUENCY SAMPLING

• US 20100194377A1
• Filed: 02/05/2009
• Published: 08/05/2010
• Est. Priority Date: 02/05/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: Sonora Medical Systems, Inc.
• Inventors: Valenti, Joseph Leo III
• Granted Patent: US 8,008,906 B2
• Time in Patent Office: Days
• US Class Current: 324/76.38
• CPC Class Codes: G01R 13/0272 for sampling

Abstract

Various embodiments provide methods, apparatuses, and systems for sampling a waveform using relatively prime sampling methods. A waveform with a first plurality of cycles and a first frequency may be sampled with a waveform sampling device. Sampling the waveform may include sampling the waveform at a sampling rate of the waveform sampling device. Sampling the waveform may include taking a sample number of samples of the waveform where the sample number may be relatively prime with respect to the number of cycles of the waveform. The sample number of samples of the waveform may be interleaved with a controller.

Claims

1. A method for sampling waveforms using relatively prime number sampling, comprising:

sampling, using a waveform sampling device, a waveform with a first plurality of cycles and a first frequency, wherein sampling the waveform includes;

sampling at a first sampling rate of the waveform sampling device; and

sampling a first sample number of samples of the waveform, wherein the first sample number is relatively prime with respect to the first plurality of cycles; and

interleaving the first sample number of samples of the waveform with a controller.

2. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein the first sample number is a prime number.

3. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein the waveform sampling device is an analog-to-digital converter.

4. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein the waveform sampling device is a sound card coupled with a computer.

5. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein the waveform is dithered.

6. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein the first sample number is a function of the first sampling rate and the first frequency.

7. The method for sampling waveforms using relatively prime number sampling of claim 6, wherein the function is approximately an inverse of a quotient of the first frequency and a product of a first cycle number and a first sampling rate of the waveform sampling device.

8. The method for sampling waveforms using relatively prime number sampling claim 1, further comprising:

sampling, with the waveform sampling device, a second waveform with a second plurality of cycles with a second frequency, wherein sampling the second waveform includes;

sampling at the first sampling rate of the waveform sampling device; and

sampling a second sample number of samples of the second waveform, wherein the second sample number is relatively prime with respect to the second plurality of full cycles; and

interleaving the second sample number of samples of the second waveform with a controller.

9. The method for sampling waveforms using relatively prime number sampling of claim 1, wherein sampling the waveform further comprises sampling a waveform transmitted through a device under test.

10. The method for sampling waveforms using relatively prime number sampling of claim 9, further comprising determining a transfer function for the device under test based on sampling the waveform transmitted through the device under test.

11. The method for sampling waveforms using relatively prime number sampling of claim 9, further comprising determining an impedance of the device under test.

12. The method for sampling waveforms using relatively prime number sampling of claim 9, further comprising determining a phase shift.

13. A method for generating waveforms for sampling using relatively prime number sampling, comprising:

determining a relatively prime sample number, wherein the relatively prime sample number is relatively prime with respect to a cycle number;

determining an adjusted frequency, wherein the adjusted frequency is;

approximately equal to a test frequency; and

a function of the relatively prime sample number, the cycle number, and a sampling rate of a waveform sampling device; and

transmitting a waveform with the adjusted frequency and the cycle number of cycles with a waveform generating device.

14. The method for generating waveforms for sampling using relatively prime number sampling of claim 13, wherein the function approximately equals the inverse of a quotient of the relatively prime sample number and a product of the cycle number and the sampling rate.

15. The method for generating waveforms for sampling using relatively prime number sampling of claim 13, wherein a user determines the test frequency.

16. The method for generating waveforms for sampling using relatively prime number sampling of claim 13, wherein the wave generating device is a digital-to-analog converter.

17. The method for generating waveforms for sampling using relatively prime number sampling of claim 16, wherein the digital-to-analog converter is a sound card coupled with a computer.

18. The method for generating waveforms for sampling using relatively prime number sampling of claim 13, further comprising:

sampling, with a waveform sampling device, a second waveform with the adjusted frequency and the cycle number of cycles, wherein sampling the second waveform includes;

sampling at the sampling rate of the waveform sampling device; and

sampling the second waveform the relatively prime sample number of times; and

interleaving the relatively prime number of samples of the second waveform with a controller.

19. The method for generating waveforms for sampling using relatively prime number sampling of claim 18, wherein the waveform is transmitted to a device under test and the second waveform is received from the device under test.

20. A system for sampling waveforms using relatively prime number sampling, comprising:

a computational device;

a waveform generating device coupled with the computational device and configured to transmit a first waveform with a plurality of cycles and a frequency; and

a waveform sampling device coupled with the computational device and configured to sample a second waveform with the plurality of cycles and the frequency a sample number of times, wherein the sample number is relatively prime with respect to the plurality of cycles.

21. The system for sampling waveforms using relatively prime number sampling of claim 20, wherein the first waveform is transmitted to a device under test from the waveform generating device and the second waveform is received from the device under test at the waveform sampling device.

22. A device for sampling waveforms using relatively prime number sampling, comprising:

means for sampling a waveform with a plurality of cycles and a frequency, wherein sampling the waveform includes;

sampling at a sampling rate; and

sampling a sample number of samples of the waveform, wherein the sample number is relatively prime with respect to the plurality of cycles; and

means for interleaving the sample number of samples of the waveform.

23. The device for sampling waveforms using relatively prime number sampling of claim 22, further comprising:

means for dithering the sample number of samples of the waveform.

24. The device for sampling waveforms of claim 22, further comprising:

means for determining a relatively prime sample number, wherein the relatively prime sample number is relatively prime with respect to a cycle number;

means for determining an adjusted frequency, wherein the adjusted frequency approximately equals a test frequency and is a function of the relatively prime sample number, the cycle number, and a sample rate; and

means for transmitting a cycle number of cycles of a waveform with the adjusted frequency.