Location determination by correcting for antenna occlusion

• US 9,507,008 B1
• Filed: 12/13/2013
• Issued: 11/29/2016
• Est. Priority Date: 12/13/2013
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Thiagarajan, Arvind
• Primary Examiner(s): Hong, Dung
• Application Number:
  US14/105,925
• Time in Patent Office: 1,082 Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence

Abstract

Systems and methods for receiving a plurality of wireless communication signals and identifying an antenna occlusion condition from the received plurality of wireless communication signals is disclosed. A correction factor may be determined based at least in part on determined signal strength corresponding to each of the received wireless communication signals. The correction factor may be used to determine a location based at least in part on the signal strength corresponding to each of the received communication signals and the determined correction factor.

Claims

1. A user device, comprising:

an antenna to receive a plurality of wireless communication signals from a plurality of wireless communication access points;

at least one memory that stores computer-executable instructions;

at least one processor that accesses the at least one memory, wherein the at least one processor executes the computer-executable instructions to;

determine a first signal strength of a first communication signal received from a first wireless communications access point at a first time;

determine a second signal strength of a second communication signal received from a second wireless communications access point at substantially the first time;

determine a third signal strength of a third communication signal received from the first wireless communications access point at a second time;

determine a fourth signal strength of a fourth communication signal received from the second wireless communications access point at substantially the second time;

determine a first change in signal strength using the first signal strength and the third signal strength;

determine a second change in signal strength using the second signal strength and the fourth signal strength;

determine that the antenna is at least partially occluded during the second time, wherein the first change or the second change in signal strength is greater than a predetermined threshold;

determine a correction factor using the first, the second, the third, and the fourth signal strengths based at least in part on the first change or the second change being greater than the predetermined threshold;

determine a first corrected signal strength by combining the correction factor with the first signal strength;

determine a second corrected signal strength by combining the correction factor with the second signal strength; and

determine a location of the user device based at least in part on the first corrected signal strength and the second corrected signal strength.

2. The user device of claim 1, wherein the at least one processor further executes the computer-executable instructions to:

determine, based at least in part on a third set of signal strengths from a third plurality of wireless communication signals received from the plurality of wireless communications access points at substantially a third time, that the occlusion condition is no longer present; and

based at least in part on the determination that the occlusion condition is no longer present, determine a second location of the user device based at least in part on the third set of signal strengths.

3. The user device of claim 2, wherein the at least one processor executes the computer-executable instructions to determine that the occlusion condition is no longer present by detecting that a magnitude of change between the second set of signal strengths and the third set of signal strengths is greater than a second predetermined threshold level.

4. The user device of claim 1, wherein to determine that the antenna is partially occluded during the second time, the at least one processor is further configured to determine a conductive element in the proximity of the antenna.

5. A method, comprising:

receiving, by a user device comprising one or more processors, a plurality of wireless communication signals;

determining, by the user device, a first signal strength corresponding to a first received wireless communication signal from a sending device at a first time;

determining, by the user device, a second signal strength corresponding to a second received wireless communication signal from the sending device at a second time after the first time;

determining that the antenna is at least partially occluded based on determining that a magnitude change between the first signal strength and the second signal strength is greater than a predetermined threshold;

determining a correction factor using the first signal strength and the second signal strength based at least in part on the magnitude change being greater than the predetermined threshold;

determining a corrected signal strength by combining the second signal strength with the correction factor; and

determine a location of the user device based at least in part on the corrected signal strength.

6. The method of claim 5, further comprising determining, by the user device and based at least in part on determining that the occlusion condition is present, a correction factor associated with the plurality of received wireless communication signals and based at least in part on the first signal strength and the second signal strength.

7. The method of claim 6, wherein determining the correction factor associated with the plurality of received wireless communication signals comprises determining a change between the first signal strength and the second signal strength.

8. The method of claim 6, further comprising determining, by the user device, a location of the user device based at least in part on the second signal strength and the correction factor.

9. The method of claim 5, wherein determining the second signal strength comprises determining, by the user device, a time series of signal strengths corresponding to the sending device.

10. The method of claim 5, wherein determining that an occlusion condition is present comprises determining, by the user device, that a magnitude of change between the first signal strength and the second signal strength is greater than a predetermined threshold level.

11. The method of claim 5, further comprising:

determining, by the user device and based at least in part on a third signal strength corresponding to a third received wireless communication signal from the sending device at a third time, that the occlusion condition is no longer present; and

determining, by the user device and based at least in part on the determination that the occlusion condition is no longer present, a location of the user device based at least in part on the third signal strength.

12. The method of claim 11, wherein determining that the occlusion condition is no longer present comprises identifying that a magnitude of change between the third signal strength and the second signal strength satisfies a predetermined criteria.

13. At least one non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors, executes a method comprising:

receiving, by a user device, a plurality of wireless communication signals;

determining, by the user device, a first signal strength corresponding to at least one of the received plurality of wireless communication signals at a first time;

determining, by the user device, a second signal strength corresponding to the at least one of the received plurality of wireless communication signals at a second time after the first time;

determining that the antenna is at least partially occluded based on determining that a magnitude change between the first signal strength and the second signal strength is greater than a predetermined threshold;

determining a correction factor associated with the plurality of received wireless communication signals based at least in part on the magnitude change between the first signal strength and the second signal strength being greater than a predetermined threshold;

determining a corrected signal strength by combining the second signal strength with the correction factor; and

determining a location of the user device based at least in part on the corrected signal strength.

14. The at least one computer-readable medium of claim 13, wherein determining the location of the user device further comprises:

triangulating based at least in part on the corrected signal strength.

15. The at least one computer-readable medium of claim 13, wherein the method further comprises:

determining, based at least in part on a third signal strength corresponding to the at least one of the received wireless communication signals at a third time, that the occlusion condition is no longer present; and

determining, based at least in part on the determination that the occlusion condition is no longer present, a location of the user device based at least in part on the third signal strength.