Method and apparatus for distinguishing direct GNSS signals from reflections

Patent metadata

Field	Value
Publication number	US-9562976-B2
Application number	US-201314039496-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Jul 31, 2013
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

A global navigation satellite system (GNSS) enabled device that is configured to distinguish reflected GNSS signals from direct GNSS signals utilizing three-dimensional models of the terrain in the proximity of the GNSS enabled device. By utilizing the identification of reflected GNSS signals, the reflected GNSS signals can be excluded and/or weighted to achieve a more accurate location determination.

First claim

What is claimed is:

1. A global navigation satellite systems (GNSS) enabled device, comprising:
a GNSS receiver configured to receive GNSS signals from a plurality of satellites, the received GNSS signals including reflected GNSS signals and direct GNSS signals; and
a processor configured to:
differentiate between the reflected GNSS signals and the direct GNSS signals; and
generate a navigation solution for the GNSS enabled device based on both the reflected GNSS signals and the direct GNSS signals, wherein the reflected GNSS signals are weighted differently from the direct GNSS signals in their respective contribution to the generation of the navigation solution,
wherein for each reflected GNSS signals, the respective weighting is continuously increased as a velocity of the GNSS enabled device becomes more orthogonal compared to a vector determined from the GNSS enabled device toward a corresponding satellite of the plurality of satellites that originated the reflected GNSS signal.

2. The GNSS enabled device of claim 1 , wherein the direct GNSS signals are GNSS signals received via direct signal paths between the GNSS enabled device and corresponding satellites of the plurality of satellites, and wherein the reflected GNSS signals are GNSS signals received via signal paths between the GNSS enabled device and corresponding satellites of the plurality of satellites that each include at least one reflected component.

3. The GNSS enabled device of claim 1 , wherein the processor is configured to utilize, in the differentiation between the reflected GNSS signals and the direct GNSS signals, a three-dimensional (3D) terrain model corresponding to a location of the GNSS enabled device or a location proximal to the location of the GNSS enabled device.

4. The GNSS enabled device of claim 3 , wherein the processor is configured to determine orbital positions of the plurality of satellites based on the received GNSS signals.

5. The GNSS enabled device of claim 4 , wherein the processor is configured to determine, based on the 3D terrain model, if a line of sight between the GNSS enabled device and each of the orbital positions of the plurality of satellites is obstructed.

6. The GNSS enabled device of claim 5 , wherein the processor is configured to identify a GNSS signal of the GNSS signals that is received from one of the plurality of satellites as a reflected GNSS signal if the line of sight between the GNSS enabled device and the orbital position of the one of the plurality of satellites is obstructed.

7. The GNSS enabled device of claim 1 , wherein the respective weighting for each of the reflected GNSS signals is based on a dot-product of the velocity of the GNSS enabled device and the vector determined from the GNSS enabled device towards the corresponding satellite of the plurality of satellites.

8. A global navigation satellite systems (GNSS) signal processing method, comprising:
receiving GNSS signals from a plurality of satellites at a GNSS enabled device, the received GNSS signals including reflected GNSS signals and direct GNSS signals;
differentiating between the reflected GNSS signals and the direct GNSS signal; and
generating a navigation solution for the GNSS enabled device based on both the reflected GNSS signals and the direct GNSS signals, including differently weighting the reflected GNSS signals and the direct GNSS signals in their respective contribution to the generation of the navigation solution,
wherein the differently weighting the reflected GNSS signals and the direct GNSS signals includes continuously increasing each respective weighting of the reflected GNSS signals as a velocity of the GNSS enabled device becomes more orthogonal compared to a vector determined from the GNSS enabled device toward a corresponding satellite of the plurality of satellites that originated the respective reflected GNSS signal.

9. The method of claim 8 , wherein the direct GNSS signals are GNSS signals received via direct signal paths and the reflected GNSS signals are GNSS signals received via signal paths that each includes at least one reflected component.

10. The method of claim 8 , wherein the differentiation between the reflected GNSS signals and the direct GNSS signals includes utilizing a three-dimensional (3D) terrain model corresponding to a location of the GNSS enabled device or a location proximal to the location of the GNSS enabled device.

11. The method of claim 10 , further comprising:
determining orbital positions of the plurality of satellites based on the received GNSS signals.

12. The method of claim 11 , further comprising:
determining which of the plurality of satellites are obstructed satellites by determining which of the plurality of satellites have an obstructed line-of-sight view of the GNSS enabled device based on the 3D terrain model, the determined orbital positions, and the location of the GNSS enabled device.

13. The method of claim 12 , further comprising:
identifying each of the plurality of satellites from which the received GNSS signals have originated based on identification information associated with the received GNSS signals.

14. The method of claim 13 , wherein the differentiation between the reflected GNSS signals and the direct GNSS signals includes determining that each of the identified GNSS signals that have been received from obstructed satellites are reflected GNSS signals.

15. The method of claim 8 , wherein the differently weighting of the reflected GNSS signals is based on a dot-product of the velocity of the GNSS enabled device and the vector determined from the GNSS enabled device towards the corresponding satellite of the plurality of satellites.

16. A global navigation satellite systems (GNSS) enabled device, comprising:
a GNSS receiver configured to receive GNSS signals from a plurality of satellites, the received GNSS signals including reflected GNSS signals and direct GNSS signals; and
a processor configured to:
differentiate between the reflected GNSS signals and the direct GNSS signals; and
generate a navigation solution for the GNSS enabled device based on both the reflected GNSS signals and the direct GNSS signals, wherein the reflected GNSS signals are weighted differently from the direct GNSS signals in their respective contribution to the generation of the navigation solution,
wherein, for each reflected GNSS signal, the respective weighting for the reflected GNSS signal is based on a dot-product of a velocity of the GNSS enabled device and a vector towards a corresponding satellite of the plurality of satellites that originated the reflected GNSS signal.

17. The GNSS enabled device of claim 16 , wherein the dot-product provides an indication of an orthogonal relationship between the velocity of the GNSS enabled device and the vector towards the corresponding satellite of the plurality of satellites that originated the reflected GNSS signal.

18. The GNSS enabled device of claim 17 , wherein the dot-product represents a varying degree of reflection error present in the reflected GNSS signal that is compensated by the respective weighting of the reflected GNSS signal.

19. The GNSS enabled device of claim 16 , wherein the processor is configured to determine orbital positions of the plurality of satellites based on the received GNSS signals.

20. The GNSS enabled device of claim 19 , wherein the processor is configured to determine, based on a 3D terrain model, if a line of sight between the GNSS enabled device and each of the orbital positions of

Assignees

• Broadcom Corp

Inventors

• Van Diggelen Frank
• Mole Stephen

Classifications

• G01S19/22

  Multipath-related issues · CPC title

• G01S19/428 Primary

  using multipath or indirect path propagation signals in position determination · CPC title