METHODS AND SYSTEMS FOR DERIVING SEED POSITION OF A SUBSCRIBER STATION IN SUPPORT OF UNASSISTED GPS-TYPE POSITION DETERMINATION IN A WIRELESS COMMUNICATION SYSTEM

• US 20130009810A1
• Filed: 09/13/2012
• Published: 01/10/2013
• Est. Priority Date: 03/22/2005
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ROWITCH, Douglas Neal, Row, Chang S., Tien, Ann Yun-En, Khushu, Sanjeev
• Application Number:
  US13/614,961
• Publication Number:
  US 20130009810A1
• Time in Patent Office: Days
• US Class Current: 342/357.25
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

In a method and system for deriving a seed position of a subscriber station in a wireless communications system in supporting unassisted GPS-type position determination is provided, the subscriber station receives overhead messages from the wireless communications system, and derives the seed position from the parameter values. The subscriber station may use a data structure in its memory and map possible parameter values to corresponding positions that may serve as the seed positions.

Claims

1. A method comprising:

obtaining a value of a parameter from a received overhead message;

accessing a data structure stored in memory of a subscriber station, the data structure including a plurality of entries comprising corresponding stored positions associated with corresponding values of at least one parameter obtainable from overhead messages;

setting a seed position, corresponding to a position estimate of the subscriber station to facilitate searching for one or more satellite transmissions of a satellite position determination system, to a stored position from an entry of the data structure associated with a corresponding value matching the value of the parameter obtained from the received overhead message; and

determining, based on the set seed position, a position of the subscriber station from signals from the satellite position determination system.

2. The method of claim 1, further comprising:

operating in an unassisted position location mode wherein significant acquisition or calculation assistance is not requested from dedicated position determination servers.

3. The method of claim 1, further comprising:

determining another position from another set of signals from the satellite position system;

obtaining one or more values of one or more parameters from another overhead message; and

storing the one or more values and the determined other position as another entry of the data structure.

4. The method of claim 1, wherein the parameter comprises a system identifier (SID), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of SID entries, a centroid location and a coverage radius associated with one of a plurality of countries.

5. The method of claim 1, wherein the parameter comprises a mobile country code (MCC), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of MCC entries, a centroid location and a coverage radius associated with one of a plurality of countries.

6. The method of claim 1, further comprising:

setting an initial seed position based on the subscriber station'"'"'s national registration, wherein setting the initial seed position comprises;

determining the subscriber station'"'"'s national registration;

determining the initial seed position based on the subscriber station'"'"'s national registration;

determining, using the initial seed position, an initial position from signals from the satellite position determination system; and

storing into one entry from the data structure the determined initial position.

7. The method of claim 1, further comprising:

assigning a hash value to each of the plurality of the entries to define a priority.

8. The method of claim 1, wherein each of the plurality of entries further comprises a respective uncertainty of a respective stored position.

9. The method of claim 8, wherein at least one uncertainty includes a maximum antenna range (MAR) associated with a base station from which at least one overhead message was received.

10. The method of claim 8, further comprising:

updating at least one entry in the data structure with a corresponding at least one determined position associated with a corresponding lower uncertainty than a corresponding at least one stored uncertainty associated with a corresponding at least one stored position, wherein updating the at least one entry comprises;

determining the at least one uncertainty associated with the corresponding at least one determined position;

determining that the at least one uncertainty associated with the corresponding at least one determined position is lower than the corresponding at least one stored uncertainty associated with the corresponding at least one stored position; and

replacing, in the at least one entry, the at least one stored position with the at least one determined position, and the at least one stored uncertainty of the corresponding at least one stored position with the at least one uncertainty associated with the corresponding at least one determined position.

11. The method of claim 1, further comprising:

determining whether a system identifier (SID) conflict exists; and

updating the data structure to reflect existence of the SID conflict.

12. The method of claim 1, wherein setting the seed position comprises:

in response to a determination that a conflict exists between the entry in the data structure and another entry in the data structure that are each associated with the value matching the value of the parameter obtained from the received overhead message, selecting one of the entry and the other entry based on a flag associated with the one of the entry and the other entry indicating one of the stored position of the entry and another stored position of the other entry is more probable than another of the stored position of the entry and the other stored position of the other entry.

13. The method of claim 1, wherein the parameter comprises one or more of:

a mobile country code (MCC), a system identifier (SID), a mobile network code (MNC), a location area code (LAC), a routing area code (RAC), a cell identity (CI), or a time zone.

14. The method of claim 1, wherein the satellite position determination system comprises a GPS system.

15. The method of claim 1, further comprising:

determining that a second position associated with a second position uncertainty lower than a position uncertainty associated with the stored position is available; and

setting the seed position to the second position.

16. A subscriber station comprising:

one or more processors;

memory comprising computer instructions that, when executed on the one or more processors, cause operations comprising;

obtaining a value of a parameter from a received overhead message;

accessing a data structure stored in the memory of the subscriber station, the data structure including a plurality of entries comprising corresponding stored positions associated with corresponding values of at least one parameter obtainable from overhead messages;

setting a seed position, corresponding to a position estimate of the subscriber station to facilitate searching for one or more satellite transmissions of a satellite position determination system, to a stored position from an entry of the data structure associated with a corresponding value matching the value of the parameter obtained from the received overhead message; and

determining, based on the set seed position, a position of the subscriber station from signals from the satellite position determination system.

17. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

operating in an unassisted position location mode wherein significant acquisition or calculation assistance is not requested from dedicated position determination servers.

18. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

determining another position from another set of signals from the satellite position system;

obtaining one or more values of one or more parameters from another overhead message; and

storing the one or more values and the determined other position as another entry of the data structure.

19. The subscriber station of claim 16, wherein the parameter comprises a system identifier (SID), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of SID entries, a centroid location and a coverage radius associated with one of a plurality of countries.

20. The subscriber station of claim 16, wherein the parameter comprises a mobile country code (MCC), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of MCC entries, a centroid location and a coverage radius associated with one of a plurality of countries.

21. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

setting an initial seed position based on the subscriber station'"'"'s national registration, wherein setting the initial seed position comprises;

determining the subscriber station'"'"'s national registration;

determining the initial seed position based on the subscriber station'"'"'s national registration;

determining, using the initial seed position, an initial position from signals from the satellite position determination system; and

storing into one entry from the data structure the determined initial position.

22. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

assigning a hash value to each of the plurality of the entries to define a priority.

23. The subscriber station of claim 16, wherein each of the plurality of entries further comprises a respective uncertainty of a respective stored position.

24. The subscriber station of claim 23, wherein at least one uncertainty includes a maximum antenna range (MAR) associated with a base station from which at least one overhead message was received.

25. The subscriber station of claim 23, wherein the memory further comprises computer instructions to cause further operations comprising:

updating at least one entry in the data structure with a corresponding at least one determined position associated with a corresponding lower uncertainty than a corresponding at least one stored uncertainty associated with a corresponding at least one stored position, wherein updating the at least one entry comprises;

determining the at least one uncertainty associated with the corresponding at least one determined position;

determining that the at least one uncertainty associated with the corresponding at least one determined position is lower than the corresponding at least one stored uncertainty associated with the corresponding at least one stored position; and

replacing, in the at least one entry, the at least one stored position with the at least one determined position, and the at least one stored uncertainty of the corresponding at least one stored position with the at least one uncertainty associated with the corresponding at least one determined position.

26. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

determining whether a system identifier (SID) conflict exists; and

updating the data structure to reflect existence of the SID conflict.

27. The subscriber station of claim 16, wherein the instructions to cause the operations of setting the seed position comprise instructions to cause operations comprising:

in response to a determination that a conflict exists between the entry in the data structure and another entry in the data structure that are each associated with the value matching the value of the parameter obtained from the received overhead message, selecting one of the entry and the other entry based on a flag associated with the one of the entry and the other entry indicating one of the stored position of the entry and another stored position of the other entry is more probable than another of the stored position of the entry and the other stored position of the other entry.

28. The subscriber station of claim 16, wherein the parameter comprises one or more of:

a mobile country code (MCC), a system identifier (SID), a mobile network code (MNC), a location area code (LAC), a routing area code (RAC), a cell identity (CI), or a time zone.

29. The subscriber station of claim 16, wherein the satellite position determination system comprises a GPS system.

30. The subscriber station of claim 16, wherein the memory further comprises computer instructions to cause further operations comprising:

determining that a second position associated with a second position uncertainty lower than a position uncertainty associated with the stored position is available; and

setting the seed position to the second position.

31. A communication apparatus comprising:

means for obtaining a value of a parameter from a received overhead message;

means for accessing a data structure stored in memory of a subscriber station, the data structure including a plurality of entries comprising corresponding stored positions associated with corresponding values of at least one parameter obtainable from overhead messages;

means for setting a seed position, corresponding to a position estimate of the subscriber station to facilitate searching for one or more satellite transmissions of a satellite position determination system, to a stored position from an entry of the data structure associated with a corresponding value matching the value of the parameter obtained from the received overhead message; and

means for determining, based on the set seed position, a position of the subscriber station from signals from the satellite position determination system.

32. The apparatus of claim 31, further comprising:

means for operating in an unassisted position location mode wherein significant acquisition or calculation assistance is not requested from dedicated position determination servers.

33. The apparatus of claim 31, further comprising:

means for determining another position from another set of signals from the satellite position system;

means for obtaining one or more values of one or more parameters from another overhead message; and

means for storing the one or more values and the determined other position as another entry of the data structure.

34. The apparatus of claim 31, wherein the parameter comprises a system identifier (SID), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of SID entries, a centroid location and a coverage radius associated with one of a plurality of countries.

35. The apparatus of claim 31, wherein the parameter comprises a mobile country code (MCC), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of MCC entries, a centroid location and a coverage radius associated with one of a plurality of countries.

36. The apparatus of claim 31, further comprising:

means for setting an initial seed position based on the subscriber station'"'"'s national registration, wherein the means for setting the initial seed position comprise;

means for determining the subscriber station'"'"'s national registration;

means for determining the initial seed position based on the subscriber station'"'"'s national registration;

means for determining, using the initial seed position, an initial position from signals from the satellite position determination system; and

means for storing into one entry from the data structure the determined initial position.

37. The apparatus of claim 31, further comprising:

means for assigning a hash value to each of the plurality of the entries to define a priority.

38. The apparatus of claim 31, wherein each of the plurality of entries further comprises a respective uncertainty of a respective stored position.

39. The apparatus of claim 38, wherein at least one uncertainty includes a maximum antenna range (MAR) associated with a base station from which at least one overhead message was received.

40. The apparatus of claim 38, further comprising:

means for updating at least one entry in the data structure with a corresponding at least one determined position associated with a corresponding lower uncertainty than a corresponding at least one stored uncertainty associated with a corresponding at least one stored position, wherein the means for updating the at least one entry comprise;

means for determining the at least one uncertainty associated with the corresponding at least one determined position;

means for determining that the at least one uncertainty associated with the corresponding at least one determined position is lower than the corresponding at least one stored uncertainty associated with the corresponding at least one stored position; and

means for replacing, in the at least one entry, the at least one stored position with the at least one determined position, and the at least one stored uncertainty of the corresponding at least one stored position with the at least one uncertainty associated with the corresponding at least one determined position.

41. The apparatus of claim 31, further comprising:

means for determining whether a system identifier (SID) conflict exists; and

means for updating the data structure to reflect existence of the SID conflict.

42. The apparatus of claim 31, wherein the means for setting the seed position comprise:

means for selecting, in response to a determination that a conflict exists between the entry in the data structure and another entry in the data structure that are each associated with the value matching the value of the parameter obtained from the received overhead message, one of the entry and the other entry based on a flag associated with the one of the entry and the other entry indicating one of the stored position of the entry and another stored position of the other entry is more probable than another of the stored position of the entry and the other stored position of the other entry.

43. The apparatus of claim 31, wherein the parameter comprises one or more of:

a mobile country code (MCC), a system identifier (SID), a mobile network code (MNC), a location area code (LAC), a routing area code (RAC), a cell identity (CI), or a time zone.

44. The apparatus of claim 31, wherein the satellite position determination system comprises a GPS system.

45. The apparatus of claim 31, further comprising:

means for determining that a second position associated with a second position uncertainty lower than a position uncertainty associated with the stored position is available; and

means for setting the seed position to the second position.

46. A non-transitory processor readable media programmed with a set of instructions executable on a processor that, when executed, cause operations comprising:

obtaining a value of a parameter from a received overhead message;

accessing a data structure stored in the memory of the subscriber station, the data structure including a plurality of entries comprising corresponding stored positions associated with corresponding values of at least one parameter obtainable from overhead messages;

setting a seed position, corresponding to a position estimate of the subscriber station to facilitate searching for one or more satellite transmissions of a satellite position determination system, to a stored position from an entry of the data structure associated with a corresponding value matching the value of the parameter obtained from the received overhead message; and

determining, based on the set seed position, a position of the subscriber station from signals from the satellite position determination system.

47. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

operating in an unassisted position location mode wherein significant acquisition or calculation assistance is not requested from dedicated position determination servers.

48. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

determining another position from another set of signals from the satellite position system;

obtaining one or more values of one or more parameters from another overhead message; and

storing the one or more values and the determined other position as another entry of the data structure.

49. The processor readable media of claim 46, wherein the parameter comprises a system identifier (SID), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of SID entries, a centroid location and a coverage radius associated with one of a plurality of countries.

50. The processor readable media of claim 46, wherein the parameter comprises a mobile country code (MCC), and wherein the data structure stored in memory includes a country table comprising, for each of a plurality of MCC entries, a centroid location and a coverage radius associated with one of a plurality of countries.

51. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

setting an initial seed position based on the subscriber station'"'"'s national registration, wherein setting the initial seed position comprises;

determining the subscriber station'"'"'s national registration;

determining the initial seed position based on the subscriber station'"'"'s national registration;

determining, using the initial seed position, an initial position from signals from the satellite position determination system; and

storing into one entry from the data structure the determined initial position.

52. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

assigning a hash value to each of the plurality of the entries to define a priority.

53. The processor readable media of claim 46, wherein each of the plurality of entries further comprises a respective uncertainty of a respective stored position.

54. The processor readable media of claim 53, wherein at least one uncertainty includes a maximum antenna range (MAR) associated with a base station from which at least one overhead message was received.

55. The processor readable media of claim 53, further comprising computer instructions to cause further operations comprising:

updating at least one entry in the data structure with a corresponding at least one determined position associated with a corresponding lower uncertainty than a corresponding at least one stored uncertainty associated with a corresponding at least one stored position, wherein updating the at least one entry comprises;

determining the at least one uncertainty associated with the corresponding at least one determined position;

determining that the at least one uncertainty associated with the corresponding at least one determined position is lower than the corresponding at least one stored uncertainty associated with the corresponding at least one stored position; and

replacing, in the at least one entry, the at least one stored position with the at least one determined position, and the at least one stored uncertainty of the corresponding at least one stored position with the at least one uncertainty associated with the corresponding at least one determined position.

56. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

determining whether a system identifier (SID) conflict exists; and

updating the data structure to reflect existence of the SID conflict.

57. The processor readable media of claim 46, wherein the instructions to cause the operations of setting the seed position comprise instructions to cause operations comprising:

in response to a determination that a conflict exists between the entry in the data structure and another entry in the data structure that are each associated with the value matching the value of the parameter obtained from the received overhead message, selecting one of the entry and the other entry based on a flag associated with the one of the entry and the other entry indicating one of the stored position of the entry and another stored position of the other entry is more probable than another of the stored position of the entry and the other stored position of the other entry.

58. The processor readable media of claim 46, wherein the parameter comprises one or more of:

a mobile country code (MCC), a system identifier (SID), a mobile network code (MNC), a location area code (LAC), a routing area code (RAC), a cell identity (CI), or a time zone.

59. The processor readable media of claim 46, wherein the satellite position determination system comprises a GPS system.

60. The processor readable media of claim 46, further comprising computer instructions to cause further operations comprising:

determining that a second position associated with a second position uncertainty lower than a position uncertainty associated with the stored position is available; and

setting the seed position to the second position.