Claims
- 1. In a wireless communication system, a method for estimating an original pilot signal, the method comprising:
receiving a CDMA signal; despreading the CDMA signal; obtaining a pilot signal from the CDMA signal; and estimating an original pilot signal using a pilot estimator that includes more than one filter and that includes a switching method for using the more than one filter, wherein the switching method uses a prediction error, and wherein the pilot estimator provides a pilot estimate.
- 2. The method as in claim 1, wherein the pilot estimator includes a first Kalman filter and a second Kalman filter.
- 3. The method as in claim 2, wherein the Kalman filters are implementing Infinite Impulse Response filters.
- 4. The method as in claim 3, wherein the first Kalman filter provides a first filtered estimate and a first prediction error, and wherein the second Kalman filter provides a second filtered estimate and a second prediction error.
- 5. The method as in claim 4, wherein the switching method uses the first prediction error and the second prediction error.
- 6. The method as in claim 5, wherein the switching method uses a first error variance and a second error variance.
- 7. The method as in claim 6, wherein the pilot estimate is obtained according to the following:
- 8. The method as in claim 7, wherein each combining coefficient is obtained through use of a posteriori probabilities function obtained according to the following:
- 9. The method as in claim 1, wherein the switching method comprises a soft-switching method.
- 10. The method as in claim 1, wherein the switching method comprises a hard-switching method.
- 11. The method as in claim 1, wherein the method is implemented in a mobile station.
- 12. A mobile station for use in a wireless communication system wherein the mobile station is configured to estimate an original pilot signal, the mobile station comprising:
an antenna for receiving a CDMA signal; a receiver in electronic communication with the antenna; a front-end processing and despreading component in electronic communication with the receiver for despreading the CDMA signal; a pilot estimation component in electronic communication with the front-end processing and despreading component for estimating an original pilot signal using a pilot estimator that includes more than one filter and that includes a switching method for using the more than one filter, wherein the switching method uses a prediction error, and wherein the pilot estimator provides a pilot estimate; and a demodulation component in electronic communication with the pilot estimation component and the front-end processing and despreading component for providing demodulated data symbols to the mobile station.
- 13. The mobile station as in claim 12, wherein the pilot estimator includes a first Kalman filter and a second Kalman filter.
- 14. The mobile station as in claim 13, wherein the Kalman filters are implementing Infinite Impulse Response filters.
- 15. The mobile station as in claim 14, wherein the first Kalman filter provides a first filtered estimate and a first prediction error, and wherein the second Kalman filter provides a second filtered estimate and a second prediction error.
- 16. The mobile station as in claim 15, wherein the switching method uses the first prediction error and the second prediction error.
- 17. The mobile station as in claim 16, wherein the switching method uses a first error variance and a second error variance.
- 18. The mobile station as in claim 17, wherein the pilot estimate is obtained according to the following:
- 19. The mobile station as in claim 18, wherein each combining coefficient is obtained through use of a posteriori probabilities function obtained according to the following:
- 20. The mobile station as in claim 12, wherein the switching method comprises a soft-switching method.
- 21. The mobile station as in claim 12, wherein the switching method comprises a hard-switching method.
- 22. A mobile station for use in a wireless communication system wherein the mobile station is configured to estimate an original pilot signal, the mobile station comprising:
means for receiving a CDMA signal; means for despreading the CDMA signal; means for obtaining a pilot signal from the CDMA signal; and means for estimating an original pilot signal using a pilot estimator that includes more than one filter and that includes a switching method for using the more than one filter, wherein the switching method uses a prediction error, and wherein the pilot estimator provides a pilot estimate.
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 60/454,378, filed on Mar. 12, 2003.
[0002] The present invention is related to the following Applications for Patent in the U.S. Patent & Trademark Office which are incorporated by reference for all purposes:
[0003] “Method And Apparatus For Pilot Estimation Using Suboptimum Expectation Maximization” by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/262,306, filed Sep. 30, 2002;
[0004] “Method And Apparatus For Pilot Estimation Using A Wiener Filter” by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/262,010, filed Sep. 30, 2002;
[0005] “Method And Apparatus For Pilot Estimation Using A Prediction Error Method With A Kalman Filter And Pseudo-Linear Regression”, by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/262,111, filed Sep. 30, 2002;
[0006] “Method And Apparatus For Pilot Estimation Using A Prediction Error Method With A Kalman Filter And A Gauss-Newton Method”, by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/262,044, filed Sep. 30, 2002;
[0007] “Method And Apparatus For Pilot Estimation Using An Adaptive Prediction Error Method With A Kalman Filter And A Gauss-Newton Method” by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/262,112, filed Sep. 30, 2002; and
[0008] “Method And Apparatus For Pilot Estimation Using Prediction Error Method” by Farrokh Abrishamkar et al., U.S. application Ser. No. 10/279,535, filed Oct. 23, 2002.
Provisional Applications (1)
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Number |
Date |
Country |
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60454378 |
Mar 2003 |
US |