System and method for A-GPS positioning of a mobile device

• US 7,920,091 B2
• Filed: 08/03/2010
• Issued: 04/05/2011
• Est. Priority Date: 12/07/2007
• Status: Expired due to Fees

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Tran, Khiem, Harper, Neil, Thomson, Martin
• Primary Examiner(s): Tarcza, Thomas H
• Assistant Examiner(s): LIU, HARRY K
• Application Number:
  US12/849,493
• Publication Number:
  US 20100302098A1
• Time in Patent Office: 245 Days
• Field of Search: 342/357.42
• US Class Current: 342/357.42
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/28 Satellite selection

Abstract

A system and method for estimating the position of a mobile device using information from a constellation of satellites. A first set of satellites of the constellation may be selected and then a second set of satellites of the constellation may be selected as a function of signals received from the first set of satellites. Data may be transmitted to the mobile device based on signals received from the second set of satellites, and a location of the device estimated based on the data. One embodiment may select the second set as a function of an intersection of coverage areas of ones of the first set of satellites. Another embodiment may select the second set as a function of one or more satellites that are not occluded by the Earth from one or more of the first set of satellites.

Claims

1. A method for determining the location of a wireless device comprising the steps of:

(a) determining a first plurality of satellites for a region in which the wireless device is located;

(b) determining a second plurality of satellites as a function of an intersection of coverage areas of ones of said first plurality of satellites;

(c) transmitting assistance data to said device, said assistance data including information from said second plurality of satellites; and

(d) estimating a location of the device from said information.

2. The method of claim 1 further comprising repeating step (a) until said first plurality of satellites is equal to or greater than a predetermined threshold.

3. The method of claim 1 wherein the first and second plurality of satellites are mutually exclusive.

4. The method of claim 1 wherein the estimated location of the device is a function of signals provided by a cellular network.

5. The method of claim 1 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

6. The method of claim 5 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

7. The method of claim 1 wherein the wireless device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

8. The method of claim 1 wherein said region is selected from the group consisting of:

a serving area of a base station serving said wireless device, an approximate area of a communications network, a city, a municipality, a county, a state, a country, a continent, and the Earth.

9. The method of claim 1 wherein said location is estimated as a function of a pseudo-measurement.

10. The method of claim 1 wherein determining a second plurality of satellites further comprises including more or less satellites in said second plurality as a function of satellite elevation.

11. A method for determining the location of a wireless device comprising the steps of:

(a) determining a first set of satellites for a region in which the wireless device is located;

(b) determining a second set of satellites as a function of one or more satellites that are not occluded by the Earth from one or more of said first set of satellites;

(c) transmitting assistance data to said device, said assistance data including information from said second set of satellites; and

(d) estimating a location of the device from said information.

12. The method of claim 11 further comprising repeating step (a) until said first set of satellites is equal to or greater than a predetermined threshold.

13. The method of claim 11 wherein there is no intersection between the first set and second set of satellites.

14. The method of claim 11 wherein the estimated location of the device is a function of signals provided by a cellular network.

15. The method of claim 11 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

16. The method of claim 15 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

17. The method of claim 11 wherein the wireless device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

18. The method of claim 11 wherein said region is selected from the group consisting of a serving area of a base station serving said wireless device, an approximate area of a communications network, a city, a municipality, a county, a state, a country, a continent, and the Earth.

19. The method of claim 11 wherein said location is estimated as a function of a pseudo-measurement.

20. The method of claim 11 wherein determining a second set of satellites further comprises including more or less satellites in said second set as a function of satellite elevation.

21. A system for determining a location of a device from signals received from a plurality of Global Navigation Satellite System (“

GNSS”

) satellites comprising;

(a) circuitry for determining a first plurality of satellites for a region in which a device is located;

(b) circuitry for determining a second plurality of satellites as a function of an intersection of coverage areas of ones of said first plurality of satellites;

(c) a transmitter for transmitting assistance data to said device, said assistance data including information from said second plurality of satellites; and

(d) circuitry for estimating a location of the device from said information.

22. The system of claim 21 wherein the first and second plurality of satellites are mutually exclusive.

23. The system of claim 21 wherein the estimated location of the device is a function of signals provided by a cellular network.

24. The system of claim 21 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

25. The system of claim 21 wherein the device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

26. The system of claim 21 wherein said region is selected from the group consisting of:

a serving area of a base station serving said wireless device, an approximate area of a communications network, a city, a municipality, a county, a state, a country, a continent, and the Earth.

27. A system for determining a location of a device from signals received from a plurality of Global Navigation Satellite System (“

GNSS”

) satellites comprising;

(a) circuitry for determining a first set of satellites for a region in which the device is located;

(b) circuitry for determining a second set of satellites as a function of one or more satellites that are not occluded by the Earth from one or more of said first set of satellites;

(c) a transmitter for transmitting assistance data to said device, said assistance data including information from said second set of satellites; and

(d) circuitry for estimating a location of the device from said information.

28. The system of claim 27 wherein there is no intersection between the first set and second set of satellites.

29. The system of claim 27 wherein the estimated location of the device is a function of signals provided by a cellular network.

30. The system of claim 27 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

31. The system of claim 27 wherein the device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

32. The system of claim 27 wherein said region is selected from the group consisting of:

a serving area of a base station serving said wireless device, an approximate area of a communications network, a city, a municipality, a county, a state, a country, a continent, and the Earth.

33. The system of claim 27 wherein the circuitry for determining a second set of satellites further comprises circuitry for including more or less satellites in said second set as a function of satellite elevation.

34. A method for estimating the position of a mobile device using information from a constellation of satellites, comprising the steps of:

(a) receiving first information from a first set of satellites of said constellation;

(b) receiving second information from a second set of satellites of said constellation wherein said second set is selected based on said first information;

(c) transmitting data based on said second information to said device; and

(d) estimating a location of said device based on said data.

35. The method of claim 34 wherein the mobile device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

36. The method of claim 34 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

37. The method of claim 36 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

38. The method of claim 34 wherein there is no intersection between the first set and second set of satellites.

39. The method of claim 34 wherein said data is assistance data.

40. The method of claim 34 wherein said first information includes coverage areas of ones of said first set of satellites.

41. The method of claim 34 wherein said first information includes whether one or more of said first set of satellites are occluded by the Earth from one or more of said second set of satellites.

42. A method for estimating the position of a mobile device using information from a constellation of satellites, comprising the steps of:

(a) selecting a first set of satellites of said constellation;

(b) selecting a second set of satellites of said constellation as a function of first signals received from said first set of satellites;

(c) transmitting to said device data based on second signals received from said second set of satellites; and

(d) estimating a location of said device based on said data.

43. The method of claim 42 wherein the mobile device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

44. The method of claim 42 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

45. The method of claim 44 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

46. The method of claim 42 wherein there is no intersection between the first set and second set of satellites.

47. The method of claim 42 wherein said data is assistance data.

48. The method of claim 42 wherein said second set is selected as a function of coverage areas of said first signals from ones of said first set of satellites.

49. The method of claim 42 wherein said second set is selected as a function of one or more satellites that are not occluded by the Earth from said first signals from ones of said first set of satellites.

50. A method for determining the location of a wireless device comprising the steps of:

(a) determining a first plurality of satellites for a region in which the wireless device is located;

(b) obtaining a satellite measurement, using said device, from at least one of said first plurality of satellites;

(c) determining a second plurality of satellites as a function of an intersection of coverage areas of said at least one satellite and at least one other satellite of said first plurality of satellites;

(d) transmitting assistance data to said device, said assistance data including information from said second plurality of satellites; and

(e) estimating a location of the device from said information.

51. The method of claim 50 wherein the estimated location of the device is a function of signals provided by a cellular network.

52. The method of claim 51 wherein the satellites are part of a Global Navigation Satellite System.

53. The method of claim 50 wherein the wireless device is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

54. The method of claim 50 wherein said region is selected from the group consisting of:

a serving area of a base station serving said wireless device, an approximate area of a communications network, a city, a municipality, a county, a state, a country, a continent, and the Earth.

55. The method of claim 50 wherein said assistance data consists of information from said at least one satellite and information from said second plurality of satellites.

56. The method of claim 50 wherein the step of estimating a location of said device includes the steps of:

(i) obtaining a satellite measurement, using said device, from ones of said second plurality of satellites using said assistance data; and

(ii) estimating a location of said device from said satellite measurements.