POSITIONING USING OBSERVER-BASED TIME-OF-ARRIVAL MEASUREMENTS

• US 20140051460A1
• Filed: 03/12/2013
• Published: 02/20/2014
• Est. Priority Date: 08/14/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: DUA, Praveen, GARIN, Lionel Jacques
• Granted Patent: US 9,066,202 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

A method of determining a position of a target device includes: sending a first measurement signal from a first known-position device; receiving the first measurement signal at a second known-position device; receiving a first acknowledgement signal from the target device at the first known-position device and at the second known-position device; determining the position of the target device using first timing information associated with the first measurement signal and the first acknowledgement signal, a first position of the first known-position device, and a second position of the second known-position device.

Claims

1. A method of determining a position of a target device, the method comprising:

sending a first measurement signal from a first known-position device;

receiving the first measurement signal at a second known-position device;

receiving a first acknowledgement signal from the target device at the first known-position device and at the second known-position device; and

determining the position of the target device using first timing information associated with the first measurement signal and the first acknowledgement signal, a first position of the first known-position device, and a second position of the second known-position device.

2. The method of claim 1 wherein the first timing information comprises a transmission time of the first measurement signal, a first time of arrival of the first acknowledgement signal in the first known-position device, a second time of arrival of the first measurement signal in the second known-position device, and a third time of arrival of the first acknowledgement signal in the second known-position device, and wherein using the first timing information comprises determining a first distance and a second distance from the target device to the first known-position device and the second known-position device, respectively, using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival.

3. The method of claim 2 wherein using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival comprises determining a difference between (1) a difference between the first time of arrival and the transmission time and (2) a difference between the third time of arrival and the second time of arrival.

4. The method of claim 1 further comprising:

receiving the first measurement signal at a third known-position device; and

receiving the first acknowledgement signal from the target device at the third known-position device;

wherein the first timing information comprises a transmission time of the first measurement signal, a first time of arrival of the first acknowledgement signal in the first known-position device, a fourth time of arrival of the first measurement signal in the third known-position device, and a fifth time of arrival of the first acknowledgement signal in the third known-position device; and

wherein using the first timing information comprises determining a third distance from the target device to the third known-position device using the fourth time of arrival and the fifth time of arrival.

5. The method of claim 1 further comprising:

sending a second measurement signal from the second known-position device;

receiving the second measurement signal at the first known-position device; and

receiving a second acknowledgement signal from the target device at the first known-position device and at the second known-position device;

wherein determining the position of the target device further comprises using second timing information associated with the second measurement signal and the second acknowledgement signal.

6. The method of claim 5 further comprising sending an exchange message from the first known-position device indicating receipt of the first acknowledgement signal, wherein the second measurement signal is sent from the second known-position device in response to the exchange message being received by the second known-position device.

7. The method of claim 5 wherein the first known-position device and the second known-position device form a measurement-observer known-position device pair, the method further comprising obtaining further timing information from a plurality of further measurement-observer known-position device pairs for the target device, and wherein determining the position of the target device further comprises using the further timing information to determine the position of the target device using trilateration.

8. An apparatus for determining a position of a target device, the apparatus comprising:

a network interface;

a control engine communicatively coupled to the network interface and configured to;

send, via the network interface, a first instruction to a first network device to act as a measurement network device to send a first measurement signal; and

send, via the network interface, a second instruction to a second network device to act as an observer network device to receive the first measurement signal, the first network device having a first known position and the second network device having a second known position; and

a position engine, communicatively coupled to the control engine and the network interface, configured to;

receive, via the network interface, first timing information associated with the first measurement signal; and

determine the position of the target device based on the first timing information, the first known position, and the second known position.

9. The apparatus of claim 8 wherein:

the first timing information comprises;

a transmission time of the first measurement signal;

a first time of arrival in the first network device of a first acknowledgement signal sent by the target device in response to receiving the first measurement signal;

a second time of arrival of the first measurement signal in the second network device; and

a third time of arrival of the first acknowledgement signal in the second network device; and

the position engine, to determine the position of the target device, is configured to determine a first distance and a second distance from the target device to the first network device and the second network device, respectively, using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival.

10. The apparatus of claim 9 wherein using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival comprises determining a difference between (1) a difference between the first time of arrival and the transmission time and (2) a difference between the third time of arrival and the second time of arrival.

11. The apparatus of claim 8 wherein:

the control engine is further configured to instruct a third network device to act as another observer network device, the third network device having a third known position;

the first timing information further comprises;

a fourth time of arrival of the first measurement signal in the third network device; and

a fifth time of arrival of a first acknowledgement signal in the third network device; and

the position engine, to determine the position of the target device, is further configured to determine a third distance from the target device to the third network device using the fourth time of arrival and the fifth time of arrival.

12. The apparatus of claim 8 wherein:

the control engine is further configured to instruct the first network device to act as the observer network device and the second network device to act as the measurement network device; and

the position engine is further configured to;

receive, via the network interface, second timing information associated with a second measurement signal sent from the second network device and received by the first network device while acting as the observer network device; and

determine the position of the target device further based on the second timing information.

13. An apparatus for determining a position of a target device, the apparatus comprising:

a network interface;

control means, communicatively coupled to the network interface, for;

sending, via the network interface, a first instruction to a first network device to act as a measurement network device to send a first measurement signal; and

sending, via the network interface, a second instruction to a second network device to act as an observer network device to receive the first measurement signal, the first network device having a first known position and the second network device having a second known position; and

position determining means, communicatively coupled to the control means and the network interface, for;

receiving, via the network interface, first timing information associated with the first measurement signal; and

determining the position of the target device based on the first timing information, the first known position, and the second known position.

14. The apparatus of claim 13 wherein:

the first timing information comprises;

a transmission time of the first measurement signal;

a first time of arrival in the first network device of a first acknowledgement signal sent by the target device in response to receiving the first measurement signal;

a second time of arrival of the first measurement signal in the second network device; and

a third time of arrival of the first acknowledgement signal in the second network device; and

the position determining means, for determining the position of the target device, is configured to determine a first distance and a second distance from the target device to the first network device and the second network device, respectively, using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival.

15. The apparatus of claim 14 wherein using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival comprises determining a difference between (1) a difference between the first time of arrival and the transmission time and (2) a difference between the third time of arrival and the second time of arrival.

16. The apparatus of claim 13 wherein:

the control means is further for instructing a third network device to act as another observer network device, the third network device having a third known position;

the first timing information further comprises;

a fourth time of arrival of the first measurement signal in the third network device; and

a fifth time of arrival of a first acknowledgement signal in the third network device; and

the position determining means, for determining the position of the target device, is further configured to determine a third distance from the target device to the third network device using the fourth time of arrival and the fifth time of arrival.

17. The apparatus of claim 13 wherein:

the control means is further configured to instruct the first network device to act as the observer network device and the second network device to act as the measurement network device; and

the position determining means is further for;

receiving, via the network interface, second timing information associated with a second measurement signal sent from the second network device and received by the first network device while acting as the observer network device; and

determining the position of the target device further based on the second timing information.

18. A processor-readable storage medium comprising processor-readable instructions configured to cause a processor to:

send a first instruction to a first network device to act as a measurement network device to send a first measurement signal;

send a second instruction to a second network device to act as an observer network device to receive the first measurement signal, the first network device having a first known position and the second network device having a second known position;

receive first timing information associated with the first measurement signal; and

determine a position of a target device based on the first timing information, the first known position, and the second known position;

wherein the first timing information is associated with the first measurement signal.

19. The processor-readable storage medium of claim 18 wherein:

the first timing information comprises;

a transmission time of the first measurement signal;

a first time of arrival in the first network device of a first acknowledgement signal sent by the target device in response to receiving the first measurement signal;

a second time of arrival of the first measurement signal in the second network device; and

a third time of arrival of the first acknowledgement signal in the second network device; and

the instructions configured to cause the processor to determine the position of the target device are configured to cause the processor to determine a first distance and a second distance from the target device to the first network device and the second network device, respectively, using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival.

20. The processor-readable storage medium of claim 19 wherein using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival comprises determining a difference between (1) a difference between the first time of arrival and the transmission time and (2) a difference between the third time of arrival and the second time of arrival.

21. The processor-readable storage medium of claim 18 wherein:

the instructions further comprise instructions configured to cause the processor to instruct a third network device to act as another observer network device, the third network device having a third known position;

the first timing information further comprises;

a fourth time of arrival of the first measurement signal in the third network device; and

a fifth time of arrival of a first acknowledgement signal in the third network device; and

the instructions configured to cause the processor to determine the position of the target device are configured to cause the processor to determine a third distance from the target device to the third network device using the fourth time of arrival and the fifth time of arrival.

22. The processor-readable storage medium of claim 18 further comprising instructions configured to cause the processor to instruct the first network device to act as the observer network device and the second network device to act as the measurement network device, wherein the instructions configured to cause the processor to determine the position of the target device are configured to cause the processor to:

receive, via the network interface, second timing information associated with a second measurement signal sent from the second network device and received by the first network device while acting as the observer network device; and

determine the position of the target device further based on the second timing information.

23. A method of determining a position of a target device, the method comprising:

sending a first instruction to a first network device to act as a measurement network device to send a first measurement signal;

sending a second instruction to a second network device to act as an observer network device to receive the first measurement signal, the first network device having a first known position and the second network device having a second known position;

receiving first timing information associated with the first measurement signal; and

determining the position of the target device based on the first timing information, the first known position, and the second known position.

24. The method of claim 23 wherein:

the first timing information comprises;

a transmission time of the first measurement signal;

a first time of arrival in the first network device of a first acknowledgement signal sent by the target device in response to receiving the first measurement signal;

a second time of arrival of the first measurement signal in the second network device; and

a third time of arrival of the first acknowledgement signal in the second network device; and

determining the position of the target device comprises determining a first distance and a second distance from the target device to the first network device and the second network device, respectively, using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival.

25. The method of claim 24 wherein using the transmission time, the first time of arrival, the second time of arrival, and the third time of arrival comprises determining a difference between (1) a difference between the first time of arrival and the transmission time and (2) a difference between the third time of arrival and the second time of arrival.

26. The method of claim 23 further comprising instructing a third network device to act as another observer network device, the third network device having a third known position, wherein:

the first timing information further comprises;

a fourth time of arrival of the first measurement signal in the third network device; and

a fifth time of arrival of a first acknowledgement signal in the third network device; and

determining the position of the target device comprises determining a third distance from the target device to the third network device using the fourth time of arrival and the fifth time of arrival.

27. The method of claim 23 further comprising:

instructing the first network device to act as the observer network device and the second network device to act as the measurement network device; and

receiving second timing information associated with a second measurement signal sent from the second network device and received by the first network device while acting as the observer network device;

wherein determining the position of the target device is further based on the second timing information.