Claims
- 1. A method comprising:
determining a non-line of sight signal condition is present or likely; and responsive thereto, deriving a reliability metric for a parameter estimate.
- 2. The method of claim 1 wherein the parameter estimate is an estimate of time of arrival (TOA) of a signal.
- 3. The method of claim 2 wherein the reliability metric is root mean square error (RMSE) of the time of arrival estimate.
- 4. The method of claim 3 wherein the time of arrival estimate is derived from a peak of a correlation function for the signal.
- 5. The method of claim 4 further comprising obtaining an indication of whether a non-line sight signal condition is present or likely based on a measure of the strength of the correlation function at the peak thereof.
- 6. The method of claim 5 wherein the measure of the strength of the correlation function at the peak thereof is energy per chip divided by total received power (Ec/I0).
- 7. The method of claim 5 wherein the measure of the strength of the correlation function at the peak thereof is the energy of the correlation function at the peak.
- 8. The method of claim 5 wherein the RMSE of the TOA estimate is derived using a lookup table.
- 9. The method of claim 8 wherein the lookup table implements a non-linear relationship between the RMSE of the TOA estimate and the strength of the correlation function at the peak thereof.
- 10. The method of claim 8 wherein the lookup table implements a relationship between the RMSE of the TOA estimate, the strength of the correlation function at the peak thereof, and the integration time used to derive the correlation function.
- 11. The method of claim 5, wherein a formula implements a relationship between the RMSE of the TOA estimate, the strength of the correlation function at the peak thereof, and the integration time used to derive the correlation function.
- 12. The methods of any of claims 1, tangibly embodied as a series of instructions stored on a processor readable medium.
- 13. A system for providing a reliability metric for a parameter estimate derived from a signal using correlation analysis comprising:
first logic for providing an indication of whether a non-line of sight signal condition is present or likely; and second logic for deriving a reliability metric for the parameter estimate responsive to the indication provided by the first logic.
- 14. The system of claim 13 wherein the parameter estimate is an estimate of time of arrival (TOA) of the signal.
- 15. The system of claim 14 wherein the reliability metric is root mean square error (RMSE) of the time of arrival estimate.
- 16. The system of claim 15 wherein the time of arrival estimate is derived from a peak of a correlation function for the signal.
- 17. The system of claim 16 wherein the first logic is configured to provide an indication of whether a non line of sight signal condition is present or likely based on a measure of the strength of the correlation function at the peak thereof.
- 18. The system of claim 17 wherein the measure of the strength of the correlation function at the peak thereof is energy per chip divided by total received power (Ec/I0).
- 19. The system of claim 17 wherein the measure of the strength of the correlation function at the peak thereof is the energy of the correlation function at the peak.
- 20. The system of claim 17 wherein the second logic is configured to derive the RMSE of the TOA estimate using a lookup table.
- 21. The system of claim 20 wherein the lookup table implements a non-linear relationship between the RMSE of the TOA estimate and the strength of the correlation function at the peak thereof.
- 22. The system of claim 20 wherein the lookup table implements a relationship between the RMSE of the TOA estimate, the strength of the correlation function at the peak thereof, and the integration time used to derive the correlation function.
- 23. The system of claim 17 wherein a formula implements a relationship between the RMSE of the TOA estimate, the strength of the correlation function at the peak thereof, and the integration time used to derive the correlation function.
- 24. The method of any of claims 1, tangibly embodied on a server.
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 60/337,875, filed on Nov. 2, 2001.
[0002] This application is related to U.S. Patent Application Serial Nos. To Be Determined, Qualcomm Dkt. Nos. 010374, 010375, and 010376, and owned in common by the assignee hereof. These applications are each fully incorporated by reference herein as though set forth in full.
Provisional Applications (1)
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Number |
Date |
Country |
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60337875 |
Nov 2001 |
US |