METHOD FOR PRECISE LOCATION DETERMINATION

• US 20140073352A1
• Filed: 09/10/2013
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ZHANG, Ning, ALDANA, Carlos Horacio
• Application Number:
  US14/023,098
• Publication Number:
  US 20140073352A1
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 13/876 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/874 takes precedence
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308

Abstract

According to embodiments, methods are presented to for determining precise location of a device by exchanging a plurality of messages with one or more devices (e.g., access points or mobile devices) in vicinity. Embodiments may calculate distance between the devices using round trip time that takes to transmit and receive signals to/from each of the devices. Using definitions that account for multiple input multiple output (MIMO) transmission, the embodiments determine precise location of a device.

Claims

1. A method for determining a distance between a first device and a second device, comprising:

at the first device, receiving a first signal from the second device;

in response to receiving the first signal, transmitting a second signal from the first device using a first antenna, wherein the first device comprises a plurality of antennas including the first antenna, and the first device uses only the first antenna and no other antenna in the plurality of antennas to transmit the second signal;

receiving one or more first timing measurements corresponding to the first and the second signals from the second device; and

determining the distance between the first device and the second device based at least on the one or more first timing measurements.

2. The method of claim 1, further comprising:

transmitting a timing measurement request to the second device, wherein the first signal is received in response to the timing measurement request.

3. The method of claim 1, further comprising:

determining one or more second timing measurements, comprising time of arrival of the first signal at the first device and time of departure of the second signal from the first device.

4. The method of claim 3, further comprising:

determining round trip time (RTT) based on the one or more first timing measurements and the one or more second timing measurements, wherein the distance is determined based at least on the round trip time.

5. The method of claim 4, wherein the RTT is determined based at least on the following equation:

RTT=(t4−

t1)−

(t3−

t2), wherein t1 represents time of departure of the first signal from the second device, t2 represents the time of arrival of the first signal at the first device, t3 represents the time of departure of the second signal from the first device and t4 represents time of arrival of the second signal at the second device.

6. The method of claim 3, further comprising:

determining time of flight (TOF) of the first signal based at least on time of departure of the first signal from the second device and the time of arrival of the first signal at the first device.

7. The method of claim 3, wherein the time of arrival of the first signal comprises the earliest time that the first signal is received by one or more antennas of the first device.

8. The method of claim 3, wherein the time of arrival of the first signal comprises arrival time of the first signal at one of the receive antennas of the first device with highest received signal strength among all of the receive antennas of the first device.

9. The method of claim 3, wherein the time of arrival of the first signal comprises a weighted sum of one or more arrival times of the first signal at one or more receive antennas of the first device.

10. The method of claim 1, wherein receiving the first signal comprises receiving the first signal with a sampling rate less than 10 nanoseconds (ns).

11. The method of claim 1, wherein receiving the first signal comprises receiving the first signal with a sampling rate equal to 0.1 nanosecond (ns).

12. The method of claim 1, wherein the wireless communications comply with one of the Institute of Electrical and Electronics Engineers (IEEE) 802.11v, 802.11ad, 802.11mc or 802.11ac standards.

13. The method of claim 1, wherein the one or more first timing measurements comprise a difference measurement between a first time stamp indicative of time of arrival of the first signal at the first device and a second time stamp indicative of time of departure of the second signal from the first device.

14. The method of claim 13, wherein determining the distance between the first device and the second device comprises:

determining round trip time (WIT) based at least on the difference measurement; and

determining the distance between the first device and the second device based at least on the determined RTT.

15. The method of claim 14, wherein the difference measurement and the RTT are determined based on the following equations:

A=t4−

t1, and RTT=Δ

−

(t3−

t2), wherein t1 represents time of departure of the first signal from the second device, t2 represents the time of arrival of the first signal at the first device, t3 represents the time of departure of the second signal from the first device, and t4 represents time of arrival of the second signal at the second device, and Δ

represents the difference measurement.

16. The method of claim 1, further comprising:

transmitting a timing measurement request to a plurality of second devices; and

determining at least three distance measurements between the first device and at least three of the plurality of second devices.

17. The method of claim 16, further comprising:

determining location of the first device based at least on the at least three distance measurements and global positioning information of devices that correspond to each of the at least three distance measurements.

18. The method of claim 1, further comprising:

transmitting one or more second timing measurements to the second device, wherein the one or more second timing measurements correspond to the first and the second signals.

19. A method for determining a distance between a first device and a second device, comprising:

by the second device, transmitting a first signal to the first device using a first antenna, wherein the second device comprises a plurality of antennas including the first antenna, and the second device uses only the first antenna and no other antenna in the plurality of antennas to transmit the first signal;

receiving a second signal from the first device in response to reception of the first signal;

determining one or more first timing measurements corresponding to the first and the second signals; and

transmitting the one or more first timing measurements to the first device.

20. The method of claim 19, further comprising:

receiving a timing measurement request, wherein the first signal is transmitted in response to the timing measurement request.

21. The method of claim 19, wherein determining the one or more first timing measurements comprises:

capturing time of departure of the first signal from the second device and time of arrival of the second signal at the second device.

22. The method of claim 21, wherein the time of arrival of the second signal comprises the earliest time that the second signal is received by one or more antennas of the second device.

23. The method of claim 21, wherein the time of arrival of the second signal comprises arrival time of the second signal at one of the receive antennas of the second device with highest received signal strength among all of the receive antennas of the second device.

24. The method of claim 21, wherein the time of arrival of the second signal comprises a weighted sum of one or more arrival times of the second signal at one or more receive antennas of the second device.

25. The method of claim 19, further comprising:

receiving one or more second timing measurements from the first device;

determining round trip time (RTT) based at least on the one or more first timing measurements and the one or more second timing measurements; and

determining the distance between the first device and the second device based at least on the RTT.

26. The method of claim 25, wherein the RTT is determined based at least on the following equation:

RTT=(t4−

t1)−

(t3−

t2), wherein t1 represents the time of departure of the first signal from the second device, t2 represents time of arrival of the first signal at the first device, t3 represents time of departure of the second signal from the first device and, t4 represents the time of arrival of the second signal at the second device.

27. The method of claim 19, wherein receiving the second signal comprises receiving the second signal with a sampling rate less than 10 nanoseconds (ns).

28. The method of claim 19, wherein receiving the second signal comprises receiving the second signal with a sampling rate equal to 0.1 nanosecond.

29. The method of claim 19, wherein the wireless communications comply with one of the Institute of Electrical and Electronics Engineers (IEEE) 802.11v, 802.11ad, 802.11mc or 802.11ac standards.

30. The method of claim 19, further comprising:

receiving one or more second timing measurements from the first device; and

determining the distance between the first device and the second device based at least on the received one or more second timing measurements.

31. The method of claim 30, wherein the one or more second timing measurements comprise a difference measurement between a first time stamp indicative of time of arrival of the first signal at the second device and a second time stamp indicative of time of departure of the second signal from the second device.

32. The method of claim 31, further comprising:

determining round trip time (RTT) based at least on the difference measurement, wherein the distance between the first device and the second device is determined based at least on the determined RTT.

33. An apparatus for determining a distance from a device, comprising:

a plurality of antennas;

a receiver configured to receive a first signal from the device using at least one of the plurality of antennas;

a transmitter configured to transmit, in response to receiving the first signal, a second signal using a first antenna of the plurality of antennas, wherein the apparatus uses only the first antenna and no other antenna in the plurality of antennas to transmit the second signal;

wherein the receiver is further configured to receive one or more first timing measurements corresponding to the first and the second signals;

a processor configured to determine the distance from the device based at least on the one or more first timing measurements;

and a memory coupled to the processor.

34. The apparatus of claim 33, wherein the transmitter is further configured to transmit a timing measurement request to the device, wherein the first signal is received in response to the timing measurement request.

35. The apparatus of claim 33, wherein the processor is further configured to determine one or more second timing measurements, comprising time of arrival of the first signal at the apparatus and time of departure of the second signal from the apparatus.

38. The apparatus of claim 35, wherein the processor is further configured to determine time of flight (TOF) of the first signal based at least on time of departure of the first signal from the second device and the time of arrival of the first signal at the apparatus.

39. The apparatus of claim 35, wherein the time of arrival of the first signal comprises the earliest time that the first signal is received by one or more antennas of the apparatus.

40. The apparatus of claim 35, wherein the time of arrival of the first signal comprises arrival time of the first signal at one of the receive antennas of the apparatus with highest received signal strength among all of the receive antennas of the apparatus.

41. The apparatus of claim 35, wherein the time of arrival of the first signal comprises a weighted sum of one or more arrival times of the first signal at one or more receive antennas of the apparatus.

42. The apparatus of claim 33, wherein the receiver is further configured to receive the first signal with a sampling rate less than 10 nanoseconds (ns).

43. The apparatus of claim 33, wherein the receiver is further configured to receive the first signal with a sampling rate equal to 0.1 nanosecond (ns).

44. The apparatus of claim 33, wherein the processor is further configured to comply with one of the Institute of Electrical and Electronics Engineers (IEEE) 802.11v, 802.11ad, 802.11mc or 802.11ac standards.

45. The apparatus of claim 33, wherein the one or more first timing measurements comprise a difference measurement between a first time stamp indicative of time of arrival of the first signal at the apparatus and a second time stamp indicative of time of departure of the second signal from the apparatus.

46. The apparatus of claim 45, the processor is further configured to:

determine round trip time (RTT) based at least on the difference measurement; and

determine the distance from the device based at least on the determined RTT.

47. The apparatus of claim 46, wherein the processor is further configured to determine the difference measurement and the RTT based on the following equations:

Δ

=t4−

t1, and RTT=Δ

−

(t3−

t2), wherein t1 represents time of departure of the first signal from the device, t2 represents the time of arrival of the first signal at the apparatus, t3 represents the time of departure of the second signal from the apparatus, and t4 represents time of arrival of the second signal at the device, and Δ

represents the difference measurement.

48. The apparatus of claim 33, wherein the transmitter is further configured to transmit a timing measurement request to a plurality of devices, and the processor is further configured to determine at least three distance measurements between the apparatus and at least three of the plurality of devices.

49. The apparatus of claim 48, wherein the processor is further configured to determine location of the apparatus based at least on the at least three distance measurements and global positioning information of devices that correspond to each of the at least three distance measurements.

50. The apparatus of claim 33, wherein the transmitter is further configured to transmit one or more second timing measurements to the device, wherein the one or more second timing measurements correspond to the first and the second signals.

36. The apparatus of claim wherein the processor is further configured to:

determine round trip time (RTT) based on the one or more first timing measurements and the one or more second timing measurements, and

determine the distance based at least on the round trip time.

37. The apparatus of claim 36, wherein the processor is further cot figured to determine RTT based at least on the following equation:

RTT=(t4−

t1)−

(t3−

t2), wherein t1 represents time of departure of the first signal from the second device, t2 represents the time of arrival of the first signal at the apparatus, t3 represents the time of departure of the second signal from the apparatus and t4 represents time of arrival of the second signal at the device.

51. An apparatus for determining a distance from a device, comprising:

a plurality of antennas;

a transmitter configured to transmit a first signal to the device using a first antenna of the plurality of antennas, wherein the apparatus uses only the first antenna and no other antenna in the plurality of antennas to transmit the first signal;

a receiver configured to receive a second signal from the first device in response to reception of the first signal;

a processor configured to determine one or more first timing measurements corresponding to the first and the second signals; and

wherein the transmitter is further configured to transmit the one or more first timing measurements to the device.

52. The apparatus of claim 51, wherein the receiver is further configured to receive a timing measurement request, wherein the transmitter is further configured to transmit the first signal in response to the timing measurement request.

53. The apparatus of claim 51, wherein the processor is further configured to capture time of departure of the first signal from the apparatus and time of arrival of the second signal at the apparatus.

54. The apparatus of claim 53, wherein the time of arrival of the second signal comprises the earliest time that the second signal is received by one or more antennas of the apparatus.

55. The apparatus of claim 53, wherein the time of arrival of the second signal comprises arrival time of the second signal at one of the receive antennas of the apparatus with highest received signal strength among all of the receive antennas of the apparatus.

56. The apparatus of claim 53, wherein the time of arrival of the second signal comprises a weighted sum of one or more arrival times of the second signal at one or more receive antennas of the apparatus.

57. The apparatus of claim 51, wherein the receiver is further configured to receive one or more second timing measurements from the device;

and the processor is further configured to determine round trip time (RTT) based at least on the one or more first timing measurements and the one or more second timing measurements, and determine the distance from the device based at least on the RTT.

58. The apparatus of claim 57, wherein the processor is further configured to determine RTT based at least on the following equation:

RTT=(t4−

t1)−

(t3−

t2), wherein t1 represents the time of departure of the first signal from the apparatus, t2 represents time of arrival of the first signal at the device, t3 represents time of departure of the second signal from the device and, t4 represents the time of arrival of the second signal at the apparatus.

59. The apparatus of claim 51, wherein the receiver is further configured to receive the second signal with a sampling rate less than 10 nanoseconds (ns).

60. The apparatus of claim 51, wherein the receiver is further configured to receive the second signal with a sampling rate equal to 0.1 nanosecond.

61. The apparatus of claim 51, wherein the wireless communications comply with one of the institute of Electrical and Electronics Engineers (IEEE) 802.11v, 802.11ad, 802.11mc or 802.11ac standards.

62. The apparatus of claim 51, wherein the receiver is further configured to receive one or more second timing measurements from the device;

and

the processor is further configured to determine the distance from the device based at least on the received one or more second timing measurements.

63. The apparatus of claim 62, wherein the one or more second timing measurements comprise a difference measurement between a first time stamp indicative of time of arrival of the first signal at the apparatus and a second time stamp indicative of time of departure of the second signal from the apparatus.

64. The apparatus of claim 63, wherein the processor is further configured to determine round trip time (RTT) based at least on the difference measurement, wherein the distance from the device is determined based at least on the determined RTT.

65. An apparatus for determining a distance from a device, comprising:

means for receiving a first signal from the device;

means for transmitting a second signal from the first device, in response to receiving the first signal and using a first antenna, wherein the apparatus comprises a plurality of antennas including the first antenna, and the first device uses only the first antenna and no other antenna in the plurality of antennas to transmit the second signal;

means for receiving one or more first timing measurements corresponding to the first and the second signals from the device; and

means for determining the distance from the device based at least on the one or more first timing measurements.

66. An apparatus for determining distance from a device, comprising:

means for transmitting a first signal to the device using a first antenna, wherein the apparatus comprises a plurality of antennas including the first antenna, and the apparatus uses only the first antenna and no other antenna in the plurality of antennas to transmit the first signal;

means for receiving a second signal from the device in response to reception of the first signal; and

means for determining one or more first timing measurements corresponding to the first and the second signals, wherein the means for transmitting is further configured to transmit the one or more first timing measurements to the device.

67. A non-transitory processor-readable medium for determining distance between a first device and a second device comprising processor-readable instructions configured to cause a processor to:

at the first device, receive a first signal from the second device;

in response to receiving the first signal, transmit a second signal from the first device using a first antenna, wherein the first device comprises a plurality of antennas including the first antenna, and the first device uses only the first antenna and no other antenna in the plurality of antennas to transmit the second signal;

receive one or more first timing measurements corresponding to the first and the second signals from the second device; and

determine the distance between the first device and the second device based at least on the one or more first timing measurements.

68. A non-transitory processor-readable medium for determining distance between a first device and a second device, comprising processor-readable instructions configured to cause a processor to:

transmit a first signal to the first device using a first antenna of the second device, wherein the second device comprises a plurality of antennas including the first antenna, and the second device uses only the first antenna and no other antenna in the plurality of antennas to transmit the first signal;

receive a second signal from the first device in response to reception of the first signal;

determine one or more first timing measurements corresponding to the first and the second signals; and

transmit the one or more first timing measurements to the first device.