Determining an angle of direct path of a signal

Patent metadata

Field	Value
Publication number	US-9686765-B2
Application number	US-201314782856-A
Country	US
Kind code	B2
Filing date	Apr 12, 2013
Priority date	Apr 12, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A signal transmitted from a mobile device is received at a device. A change in angle-of-arrival (AoA) of the signal is computed as the mobile device moves from a first location to a second location. A first distance and a second distance of the mobile from the device corresponding to the first and second locations, respectively are computed. A displacement of the mobile device from the first location to the second location is computed based on mobility information provided by a sensor of the mobile device. A change in an angle of direct path (ANDP) of the signal is computed based on the first distance, the second distance, and the displacement. The ANDP is determined based on a comparison of the change in AoA to the change in ANDP.

First claim

What is claimed is:

1. A device comprising:
a receiver to receive a signal transmitted from a mobile device when the mobile device is at a first location and a second location;
a signal processing unit to:
compute a change in angle-of-arrival (AoA) of the signal when the mobile device moves from the first location to the second location;
compute a first distance and a second distance of the mobile device to the device corresponding to the first and second locations, respectively;
determine a displacement of the mobile device from the first location to the second location based on mobility information provided by a sensor of the mobile device;
compute a change in an angle of direct path (ANDP) of the signal based on the first distance, the second distance, and the displacement; and
determine the ANDP based on a comparison of the change in AoA to the change in ANDP.

2. The device of claim 1 , wherein a particular AoA that changes between the first and second locations in a substantially similar value as the computed change in ANDP is identified as the ANDP.

3. The device of claim 2 , wherein the AoA includes at least one angle of reflected path and the ANDP.

4. The device of claim 1 , wherein the first and second distances are computed based on at least one of information available at a physical (PHY) layer of the mobile device, received signal strength indicator (RSSI) of the signal, round-trip time (RTT) of the signal, and time-of-arrival (ToA) of the signal.

5. The device of claim 4 , wherein the PHY layer information includes channel state information (CSI).

6. The device of claim 1 , wherein the sensor of the mobile device includes at least one of an accelerometer, a gyroscope, and a compass.

7. The device of claim 1 , wherein the device comprises at least one of a base station, a wireless access point (AP), a cellular base station, a second mobile device, and any computing device comprising a transmitter for transmitting signals.

8. The device of claim 1 , wherein the ANDP is usable for performing a plurality of functionalities comprising at least one of localizing a plurality of mobile devices connected to the device, establishing secure connectivity in a network of the device, and admission control of a plurality of mobile devices requesting connection.

9. The device of claim 1 , wherein the AoA comprises a set of angles of arrivals corresponding to multiple paths of the signal, the signal processing unit to determine the ANDP based on a comparison of the change in AoA to the change in ANDP by identifying a path from the multiple paths of the signal having a change in angle of arrival that is substantially equal to the change in the ANDP.

10. The device of claim 9 , further comprising:
determining the path of the signal corresponding to the angle of the direct path.

11. A method for determining an angle of direct path (ANDP) of a signal transmitted from a mobile device, the method comprising:
computing, at an access point (AP), a change in angle-of-arrival (AoA) of the signal as the mobile device moves from a first location to a second location;
computing a first distance and a second distance of the mobile device to the AP when the mobile device is at the first and second locations, respectively;
determining a displacement of the mobile device from the first location to the second location based on mobility information provided by a sensor of the mobile device;
computing a change in the ANDP of the signal based on the first distance, second distance, and displacement; and
determining the ANDP based on a comparison of the change in AoA to the change in ANDP, wherein determining the ANDP includes identifying the ANDP from a plurality of AoAs that includes at least one angle of reflected path and the ANDP of the signal.

12. The method of claim 11 , wherein determining the ANDP comprises identifying a particular AoA whose change as the mobile device moves from the first location to the second location is substantially equal to the computed change in ANDP.

13. The method of claim 11 , wherein the first and second distances are computed based on at least one of information available at a physical (PHY) layer of the mobile device, received signal strength indicator (RSSI) of the signal, round-trip time (RTT) of the signal, and time-of-arrival (ToA) of the signal.

14. The method of claim 13 , wherein the PHY layer information comprises channel state information (CSI).

15. The method of claim 11 , wherein the sensor of the mobile device comprises at least one of an accelerometer, a gyroscope, and a compass.

16. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processor of an access point, cause the processor to:
receive a signal transmitted from a mobile device when the mobile device is at a first location and a second location;
compute a change in angle-of-arrival (AoA) of the signal as the mobile device moves from the first location to the second location;
compute a first distance and a second distance of the mobile device from the AP when the mobile device is at the first location and the second location, respectively, based on information available on at least one of a physical (PHY) layer and a software driver of the mobile device;
compute a distance between the first location and the second location based on mobility information provided by at least one sensor of the mobile device;
compute a change in the ANDP of the signal based on the first distance, second distance, and the distance between the first and second locations; and
determine the ANDP based on a comparison of the computed change in AoA to the computed change in ANDP, wherein the ANDP is identified as a particular AoA whose value changes in substantially a same value as the computed change in ANDP.

17. The non-transitory computer-readable storage medium of claim 16 , wherein the AoA includes at least one angle of multipath reflection of the signal and the ANDP, wherein the processor is further to distinguish between the at least one angle of multipath reflection of the signal and the ANDP based on the computed change in the ANDP and the computed change in the AoA.

Assignees

• Hewlett Packard Development Co Lp
• Hewlett Packard Entpr Dev Lp

Inventors

• Sen Souvik
• Lee Jeongkeun
• Kim Kyu-Han

Classifications

• G01S5/0218

  Multipath in signal reception · CPC title

• G01S5/12

  by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial · CPC title

• H04W4/023

  using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds · CPC title

• H04W64/00 Primary

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title

• G01S3/04

  Details · CPC title