SPUR DETECTION, CANCELLATION AND TRACKING IN A WIRELESS SIGNAL RECEIVER

• US 20140140440A1
• Filed: 11/21/2012
• Published: 05/22/2014
• Est. Priority Date: 11/21/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: SUN, Qinfang, CHENG, Hao-Jen, HUANG, Chiao-Cheng
• Granted Patent: US 9,065,686 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

A method and device for processing spur components associated with a received wireless signal are disclosed. In one embodiment, the method includes first selecting a sub-band of a spectral band of the received signal. The selected sub-band is scanned, and a detection routine is executed to detect a spur within the scanned sub-band having a peak magnitude above a predetermined threshold. The spur frequency is determined, and the spur may be removed by a cancellation unit based on the determined frequency. The method also includes tracking the frequency of the spur to ensure continued suppression over time and under dynamic conditions.

Claims

1. A method of processing spur components associated with a wireless signal, the method comprising:

selecting a sub-band of a spectral band of a received signal;

scanning the sub-band;

detecting a spur within the scanned sub-band having a peak magnitude above a predetermined threshold; and

determining a frequency associated with the spur.

2. The method of claim 1, further comprising:

cancelling the detected spur based on the determined frequency; and

tracking the frequency of the spur.

3. The method of claim 1, wherein the detecting includes differentially phase-detecting spur components associated with the spur.

4. The method of claim 1, wherein the scanning is based upon a sensitivity-versus-time determination.

5. The method of claim 2, wherein the tracking comprises:

storing initial information associated with the spur;

detecting any frequency changes associated with the spur; and

updating the storing to reflect the detected frequency changes.

6. The method of claim 1, wherein the scanning includes scanning a first frequency sub-band, then scanning a second frequency sub-band that partially overlaps the first frequency sub-band.

7. The method of claim 6, wherein the first frequency sub-band is different than the second frequency sub-band.

8. The method of claim 1, further comprising:

iteratively detecting additional spurs; and

prioritizing the detecting based on peak magnitudes.

9. A receiver comprising:

spur search logic to detect and identify a spur and a frequency associated with the spur;

a filter to cancel the spur; and

a tracker to detect changes in the spur frequency and to update the filter.

10. The receiver of claim 9, wherein the receiver comprises a wireless receiver.

11. The receiver of claim 9, wherein:

the filter is configured to cancel multiple spurs; and

the tracker comprises memory to store parameters associated with the multiple spurs.

12. The receiver of claim 9, wherein the filter comprises a distributed set of notch filters, each notch filter configured to cancel a spur frequency.

13. The receiver of claim 9, wherein the spur search logic comprises:

a fast Fourier transform (FFT) engine having a first output with a first phase and a second output with a second phase, the first phase different from the second phase; and

a differential detection unit to detect a spur based on the first and second outputs.

14. The receiver of claim 9, wherein the spur search logic includes a scanning unit to scan sub-bands of a spectral band of a received signal.

15. The receiver of claim 14, wherein the scanning unit scans multiple sub-bands that at least partially overlap.

16. A wireless system comprising:

memory to store system platform hardware information and expected spur information associated with the system platform hardware;

a measurement software layer having access to the memory; and

a receiver responsive to the measurement software layer to;

select a sub-band of a spectral band of a received signal;

scan the sub-band;

detect a spur within the scanned sub-band having a peak magnitude above a predetermined threshold; and

determine a frequency associated with the spur.

17. The wireless system of claim 16 embodied as a mobile station.

18. The wireless system of claim 16, wherein the system platform hardware information includes hardware from at least one of a general purpose computer, a tablet computer, a smartphone, a laptop computer, and a GPS location device.

19. The wireless system of claim 18, wherein the expected spur information comprises expected harmonic frequency spurs commonly associated with the system platform hardware.

20. A non-transitory computer readable medium storing computer readable instructions for machine execution of a method comprising:

selecting a sub-band of a spectral band of a received signal;

scanning the sub-band;

detecting a spur within the scanned sub-band having a peak magnitude above a predetermined threshold; and

determining a frequency associated with the spur.

21. The non-transitory computer readable medium of claim 20, further comprising:

cancelling the detected spur based on the determined frequency; and

tracking the frequency of the spur.

22. The non-transitory computer readable medium of claim 20, wherein the detecting includes differentially phase-detecting spur components associated with the spur.

23. The non-transitory computer readable medium of claim 20, wherein the tracking comprises:

storing initial information associated with the spur;

detecting any frequency changes associated with the spur; and

updating the storing to reflect the detected frequency changes.