Error mitigation in doppler based satellite positioning system measurements

Patent metadata

Field	Value
Publication number	US-10871576-B2
Application number	US-201816108019-A
Country	US
Kind code	B2
Filing date	Aug 21, 2018
Priority date	May 16, 2018
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

Disclosed embodiments facilitate accuracy and decrease error in terrestrial positioning systems, including errors induced by multipath (e.g. ground reflections) in doppler based measurements of SVs. In some embodiments, one or more Global Navigation Satellite System (GNSS) doppler measurements and one or more corresponding GNSS pseudorange measurements for one or more satellites may be obtained. One or more GNSS doppler estimates corresponding to the one or more GNSS doppler measurements may be determined, wherein for a GNSS doppler measurement, the corresponding GNSS doppler estimate may be determined based, in part, on the GNSS doppler measurement and a GNSS pseudorange measurement corresponding to the GNSS doppler measurement. A speed of the UE may be determined based, in part, on the one or more GNSS doppler estimates.

First claim

What is claimed is:

1. A method of determining a speed of a user equipment (UE), the method comprising:
measuring Global Navigation Satellite System (GNSS) Doppler measurements and corresponding GNSS pseudorange measurements for GNSS satellites;
determining one or more GNSS Doppler estimates corresponding to the GNSS Doppler measurements, wherein for a GNSS Doppler measurement, a corresponding GNSS Doppler estimate is determined based, in part, on the GNSS Doppler measurement and a GNSS pseudorange measurement corresponding to the GNSS Doppler measurement; and
determining the speed of the UE based, at least in part, on the GNSS Doppler estimates.

2. The method of claim 1 , wherein the corresponding GNSS Doppler estimate is determined based further on one or more GNSS environmental parameters associated with the GNSS Doppler measurement.

3. The method of claim 2 , wherein the one or more GNSS environmental parameters associated with the GNSS Doppler measurement comprise one or more of:
a GNSS timestamp associated with the GNSS Doppler measurement; or
a GNSS position fix associated with the GNSS Doppler measurement; or
a GNSS position fix uncertainty associated with the GNSS Doppler measurement; or
a GNSS Heading and GNSS heading uncertainty associated with the GNSS Doppler measurement; or
Dilution of Precision parameters associated with the GNSS Doppler measurement; or
a type of position fix associated with the GNSS Doppler measurement.

4. The method of claim 1 , wherein determining the corresponding GNSS Doppler estimate comprises:
determining, for the GNSS Doppler measurement, a correction, wherein the correction is determined based on the GNSS Doppler measurement and the pseudorange measurement corresponding to the GNSS Doppler measurement; and
applying the correction to the GNSS Doppler measurement to obtain the corresponding GNSS Doppler estimate.

5. The method of claim 4 , wherein the correction is determined further based on at least one of: one or more Inertial Measurement Unit (IMU) measurements, or one or more sensor measurements by the UE.

6. The method of claim 4 , wherein the correction is determined based on a mathematical model.

7. The method of claim 1 , wherein determining the corresponding GNSS Doppler estimate comprises:
predicting the corresponding GNSS Doppler estimate based on the GNSS Doppler measurement and the GNSS pseudorange measurement corresponding to the GNSS Doppler measurement, wherein the corresponding GNSS Doppler estimate is predicted using a predictive model based on machine learning.

8. The method of claim 7 , wherein the predictive model is based on at least one of:
a Generalized Additive Model (GAM), or
a Recursive Neural Network (RNN), or
a Convolutional Neural Network (CNN), or
a Fully Connected Network (FCN), or
an adaptive boosting model, or
a Generative Adversarial Network (GAN), or
a combination thereof.

9. The method of claim 7 , wherein the corresponding GNSS Doppler estimate is predicted based in part on one or more of: Inertial Measurement Unit (IMU) measurements, or sensor measurements by the UE.

10. The method of claim 1 , further comprising:
determining, based on the speed of the UE over a time interval, a distance travelled by the UE.

11. A User Equipment (UE) comprising:
a Global Navigation Satellite System (GNSS) receiver capable of receiving GNSS signals, wherein the GNSS receiver is configured to measure GNSS Doppler measurements and corresponding GNSS pseudorange measurements for GNSS satellites; and
a processor coupled to the GNSS receiver, wherein the processor is configured to:
determine GNSS Doppler estimates corresponding to the one or GNSS Doppler measurements, wherein for a GNSS Doppler measurement, a corresponding GNSS Doppler estimate is determined based, in part, on the GNSS Doppler measurement and a GNSS pseudorange measurement corresponding to the GNSS Doppler measurement; and
determine a speed of the UE based, at least in part, on the GNSS Doppler estimates.

12. The UE of claim 11 , wherein processor is configured to determine the corresponding GNSS Doppler estimate based further on one or more GNSS environmental parameters associated with the GNSS Doppler measurement.

13. The UE of claim 12 , wherein the one or more GNSS environmental parameters associated with the GNSS Doppler measurement comprise one or more of:
a GNSS timestamp associated with the GNSS Doppler measurement; or
a GNSS position fix associated with the GNSS Doppler measurement; or
a GNSS position fix uncertainty associated with the GNSS Doppler measurement; or
a GNSS Heading and GNSS heading uncertainty associated with the GNSS Doppler measurement; or
Dilution of Precision parameters associated with the GNSS Doppler measurement; or
a type of position fix associated with the GNSS Doppler measurement.

14. The UE of claim 11 , wherein to determine the corresponding GNSS Doppler estimate, the processor is configured to:
determine, for the GNSS Doppler measurement, a correction, wherein the correction is determined based on the GNSS Doppler measurement and the pseudorange measurement corresponding to the GNSS Doppler measurement; and
apply the correction to the GNSS Doppler measurement to obtain the corresponding GNSS Doppler estimate.

15. The UE of claim 14 , wherein the correction is determined further based on at least one of: one or more Inertial Measurement Unit (IMU) measurements, or one or more sensor measurements by the UE.

16. The UE of claim 14 , wherein the correction is determined based on a mathematical model.

17. The UE of claim 11 , wherein to determine the corresponding GNSS Doppler estimate, processor is configured to:
predict the corresponding GNSS Doppler estimate based on the GNSS Doppler measurement and the GNSS pseudorange measurement corresponding to the GNSS Doppler measurement, wherein the corresponding GNSS Doppler estimate is predicted using a predictive model based on machine learning.

18. The UE of claim 17 , wherein the predictive model is based on at least one of:
a Generalized Additive Model (GAM), or
a Recursive Neural Network (RNN), or
a Convolutional Neural Network (CNN), or
a Fully Connected Network (FCN), or
an adaptive boosting model, or
a Generative Adversarial Network (GAN), or
a combination thereof.

19. The UE of claim 17 , wherein the corresponding GNSS Doppler estimate is predicted based in part on one or more of: Inertial Measurement Unit (IMU) measurements, or sensor measurements by the UE.

20. The UE of claim 11 , wherein processor is further configured to:
determine, based on the speed of the UE over a time interval, a distance travelled by the UE.

21. A User Equipment (UE) comprising:
means for measuring GNSS Doppler measurements and corresponding GNSS pseudorange measurements for GNSS satellites;
means for determining one or more GNSS Doppler estimates corresponding to the GNSS Doppler measurements, wherein for a GNSS Doppler measurement, a corresponding GNSS Doppler estimate is determined based, in part, on the GNSS Doppler measurement and a GNSS pseudorange measurement corresponding to the GNSS Doppler measurement; and
means for determining a speed of the UE based, at least in part, on the GNSS Doppler estimates.

22. The UE of claim 21 , wherein the corresponding GNSS Doppler estimate is determined based further on one or more GNSS environmental parameters associated with the GNSS Doppler measurement.

23.

Assignees

• Qualcomm Inc

Inventors

• Nirula Gautam
• Morrison William
• Jee Songwon

Classifications

• G01S19/52 Primary

  Determining velocity · CPC title

• G01S19/49

  whereby the further system is an inertial position system, e.g. loosely-coupled · CPC title

• G01S19/47

  the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial · CPC title

• G01S19/40 Primary

  Correcting position, velocity or attitude · CPC title

• G01S19/29

  carrier {including Doppler,} related {(G01S19/246 takes precedence)} · CPC title