Systems and methods for estimating whether a receiver is inside or outside a building

Patent metadata

Field	Value
Publication number	US-10175364-B2
Application number	US-201514749593-A
Country	US
Kind code	B2
Filing date	Jun 24, 2015
Priority date	Jul 1, 2014
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Systems and methods for estimating whether a receiver is indoors or outdoors. Certain approaches evaluate data associated with a network of beacons to determine whether the receiver is indoors or outdoors. Such evaluation may include any of determining whether azimuthal angles corresponding to the beacons meet an azimuthal angle condition, determining whether elevation angles corresponding to the beacons meet an elevation angle condition, determining whether signal strengths corresponding to the beacons meet a signal strength condition, and determining whether other measurements associated with the beacons meet other measurement conditions.

First claim

The invention claimed is:

1. A method for estimating whether a receiver is indoors or outdoors, wherein the method comprises:
determining data associated with a plurality of beacons that specifies, for each of the beacons, (i) an azimuthal angle corresponding to the position of that beacon, (ii) an elevation angle corresponding to the position of that beacon, and (iii) a signal strength corresponding to that beacon;
determining that (i) any azimuthal angle range of n azimuthal angle ranges does not include a predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, any elevation angle range of m elevation angle ranges does not include a predetermined number of elevation angles from the elevation angles corresponding to the beacons, or any signal strength of the signal strengths does not exceed a minimum signal strength threshold value, or (ii) each azimuthal angle range of the n azimuthal angle ranges includes the predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, each elevation angle range of the m elevation angle ranges includes the predetermined number of elevation angles from the elevation angles corresponding to the beacons, and the signal strengths exceed the minimum signal strength threshold value; and
estimating, using one or more processors, whether the receiver is indoors or outdoors based on (i) whether the azimuthal angles corresponding to the beacons meet an azimuthal angle condition, (ii) whether the elevation angles corresponding to the beacons meet an elevation angle condition, and (iii) whether the signal strengths corresponding to the beacons meet a signal strength condition by:
estimating that the receiver is indoors after determining that any azimuthal angle range of n azimuthal angle ranges does not include the predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, any elevation angle range of m elevation angle ranges does not include the predetermined number of elevation angles from the elevation angles corresponding to the beacons, or any signal strength of the signal strengths does not exceed the minimum signal strength threshold value; and
estimating that the receiver is outdoors after determining that each azimuthal angle range of the n azimuthal angle ranges includes the predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, each elevation angle range of the m elevation angle ranges includes the predetermined number of elevation angles from the elevation angles corresponding to the beacons, and the signal strengths exceed the minimum signal strength threshold value.

2. The method of claim 1 , wherein the method comprises:
determining, for each of the beacons, a median signal strength based on two or more signal strengths measured for two or more signals that were transmitted by that beacon,
wherein the data specifying, for each of the beacons, the signal strength corresponding to that beacon is the median signal strength for that beacon,
wherein the minimum signal strength threshold value is a median signal strength threshold value,
wherein the receiver is estimated to be indoors when any azimuthal angle range of the n azimuthal angle ranges does not include the predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, when any elevation angle range of the m elevation angle ranges does not include the predetermined number of elevation angles from the elevation angles corresponding to the beacons, or when any median signal strength of the median signal strengths corresponding to the beacons does not exceed the median signal strength threshold value; and
wherein the receiver is estimated to be outdoors when each azimuthal angle range of the n azimuthal angle ranges includes the predetermined number of azimuthal angles from the azimuthal angles corresponding to the beacons, when each elevation angle range of the m elevation angle ranges includes the predetermined number of elevation angles from the elevation angles corresponding to the beacons, and when the median signal strengths corresponding to the beacons exceed the median signal strength threshold value.

3. The method of claim 1 , wherein the beacons are satellites.

4. The method of claim 1 , wherein the beacons are terrestrial transmitters.

5. The method of claim 1 , wherein n is at least four, and m is at least four.

6. A method for estimating whether a receiver is indoors or outdoors, the method comprising:
determining data associated with a plurality of beacons that specifies, for each of the beacons, an azimuthal angle corresponding to the position of that beacon;
determining that (i) each of the azimuthal angles corresponding to the beacons are separated from each other by at least 30 degrees of angular separation, or two or more of the azimuthal angles corresponding to the beacons are not separated from each other by at least 30 degrees of angular separation, wherein the beacons include at least six beacons, or (ii) each azimuthal angle range of n azimuthal angle ranges includes at least one of the azimuthal angles corresponding to the beacons, or any azimuthal angle range of the n azimuthal angle ranges does not include at least one of the azimuthal angles corresponding to the beacons, wherein n is at least four, and wherein none of the azimuthal angle ranges from the n azimuthal angle ranges overlap with each other by more than ten degrees; and
estimating, using one or more processors, whether the receiver is indoors or outdoors based on whether the azimuthal angles corresponding to the beacons meet an azimuthal angle condition by:
estimating that the receiver is outdoors after determining that each of the azimuthal angles corresponding to the beacons are separated from each other by at least 30 degrees of angular separation, and estimating that the receiver is indoors after determining that two or more of the azimuthal angles corresponding to the beacons are not separated from each other by at least 30 degrees of angular separation; or
estimating that the receiver is outdoors after determining that each azimuthal angle range of n azimuthal angle ranges includes at least one of the azimuthal angles corresponding to the beacons, and estimating that the receiver is indoors after determining that any azimuthal angle range of the n azimuthal angle ranges does not include at least one of the azimuthal angles corresponding to the beacons.

7. The method of claim 6 , wherein the azimuthal angle condition specifies that each of the azimuthal angles corresponding to the beacons must be separated from each other by at least 30 degrees of angular separation, wherein the beacons include at least six beacons, and wherein the method comprises:
estimating that the receiver is indoors when two or more of the azimuthal angles corresponding to the beacons are not separated from each other by at least 30 degrees of angular separation; and
estimating that the receiver is outdoors when each of the azimuthal angles corresponding to the beacons are separated from each other by at least 30 degrees of angular separation.

8. The method of claim 6 , wherein the azimuthal angle condition specifies that each azimuthal angle range of n azimuthal angle ranges must include at least one of the azimuthal angles corresponding to the beacons, wherein n is at least four, and wherein none of the azimuthal angle ranges from the n azimuthal angle ranges overlap with each other by more than ten degrees, and wherein the method comprises:
estimating that the receiver is indoors when any azimuthal angle range of the n azimuthal angle ranges does not include at least one of the azimuthal angles correspond

Assignees

• Nextnav Llc

Inventors

• Venkataraman Jagadish
• Pattabiraman Ganesh

Classifications

• G01S5/015

  between indoor and outdoor environments · CPC title

• G01S19/46 Primary

  the supplementary measurement being of a radio-wave signal type · CPC title

• G01S19/22 Primary

  Multipath-related issues · CPC title

• G01S19/24

  Acquisition or tracking {or demodulation} of signals transmitted by the system {(synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073)} · CPC title

• G01S1/08

  Systems for determining direction or position line · CPC title