Wireless link quality using location based learning

• US 6,697,644 B2
• Filed: 02/06/2001
• Issued: 02/24/2004
• Est. Priority Date: 02/06/2001
• Status: Expired due to Term

• Current Assignee: F Poszat Hu LLC (Intellectual Ventures LLC)
• Original Assignee: Kathrein-Werke KG. (Kathrein SE)
• Inventors: Wu, Jiangfeng, Scherzer, Shimon B., Wong, Piu Bill, Tesler, Alexander V.
• Primary Examiner(s): Nguyen; Lee
• Application Number:
  US09/777,613
• Publication Number:
  US 20020146983A1
• Time in Patent Office: 1,113 Days
• Field of Search: 455/562,25,446,449,422,67.11 342/367,368,369,377
• US Class Current: 455/562.1
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

The invention provides optimization of communication links by using a control loop with a relatively long time constant and adjusting particular communication links based upon feedback from a virtual communication unit associated with a communication link. A preferred embodiment of the invention optimizes wireless links in a point to multipoint system, such as a cellular communication system, by dividing a service area into segments and adjusting an antenna beam associated with a segment when a mobile unit is operable therein. This preferred embodiment results in convergence upon an optimized communication link over time and is suitable for use even with highly mobile systems. Preferred embodiments of the invention provide control loops for location or segment optimization as well as for individual optimization.

Claims

1. A method for optimizing a communication link, said method comprising:

dividing a service area associated with a first communication system into a plurality of segments;

associating a unique link configuration with each segment of said plurality of segments;

implementing a control loop for a first segment of said plurality of segments when a remote communication system is operating therein, whereby a first link configuration of said unique link configurations associated with said first segment is adjusted as a function of link conditions experienced by said remote communication system, wherein said implementing a control loop for a first segment comprises;

determining a position of said first remote communication system and therefore a segment of said service area said first remote communication system is operable within;

identifying said first link configuration associated with said determined segment;

providing a communication link to said first remote communication system using said identified first link configuration;

monitoring a communication attribute of said communication link provided using said identified first link configuration;

determining an alternative link configuration for use with said determined segment;

providing a communication link to said first remote communication system using said alternative link configuration;

monitoring a communication attribute of said communication link provided using said alternative link configuration; and

determining a link configuration to use in providing a communication link in the future based at least in part on said communication attributes monitored with respect to said identified first link configuration and said alternative link configuration; and

implementing a control loop for a second segment of said plurality of segments when said remote communication system is operating therein, whereby a second link configuration of said unique link configurations associated with said second segment is adjusted as a function of link conditions experienced by said remote communication system.

2. The method of claim 1, wherein said service area comprises a cell of a cellular communication system.

3. The method of claim 2, wherein said unique link configurations associated with said segments provide information with respect to characteristics of a wireless link.

4. The method of claim 3, wherein said unique link configurations comprise an antenna beam forming attribute.

5. The method of claim 4, wherein said antenna beam forming attribute comprises an antenna beam width, and wherein said adjusting said link configuration associated with at least one of said first segment and said second segment comprises narrowing said antenna beam width.

6. The method of claim 4, wherein said antenna beam forming attribute comprises an antenna beam orientation, and wherein said adjusting said link configuration associated with at least one of said first segment and said second segment comprises changing said antenna beam orientation.

7. The method of claim 6, wherein said antenna beam orientation comprises an azimuthal aspect, and wherein said changing said antenna beam orientation comprises changing said azimuthal aspect.

8. The method of claim 6, wherein said antenna beam orientation comprises an elevation aspect, and wherein said changing said antenna beam orientation comprises changing said elevation aspect.

9. The method of claim 4, wherein said antenna beam forming attribute comprises an antenna beam length, and wherein said adjusting said link configuration associated with at least one of said first segment and said second segment comprises changing said antenna beam length.

10. The method of claim 3, wherein said wireless link is a forward link from a base transceiver station of said cell to a communication system in communication therewith.

11. The method of claim 10, wherein said first remote communication system comprises a cellular telephone handset.

12. The method of claim 1, wherein a size of segments of said plurality of segments is based at least in part on a level of resolution available in determining a position of said first remote communication system.

13. The method of claim 12, wherein said determining a position of said first remote communication system comprises:

determining an angle of arrival of a signal associated with said first remote communication system; and

determining a distance to said first remote communication system.

14. The method of claim 12, wherein said size of segments is approximately 100 m by 100 m.

15. The method of claim 1, wherein said determining a position of said first remote communication system comprises:

determining an angle of arrival of a signal associated with said first remote communication system; and

determining a distance to said first remote communication system.

16. The method of claim 1, wherein said communication attribute monitored comprises set point information.

17. The method of claim 1, wherein said communication attribute monitored comprises a frame error rate.

18. The method of claim 1, wherein said communication attribute monitored comprises a ratio of average bit energy to noise energy.

19. The method of claim 1, wherein said determining an alternative link configuration comprises:

determining if said identified first link configuration is at a system limit and, if so, determining said alternative link configuration to back off of said system limit.

20. The method of claim 1, wherein said determining a link configuration to use comprises:

determining one of said identified first link configuration and said alternative link configuration to use in providing a communication link in the future.

21. The method of claim 1, wherein implementing a control loop for a first segment comprises:

limiting an extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment.

22. The method of claim 21, wherein implementing a control loop for a first segment further comprises:

implementing a control loop for said remote communication system during a time in which the extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment are limited.

23. The method of claim 21, wherein said limiting an extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment is provided at least in part through a determination of a number of link condition reports associated with said remote communication system.

24. The method of claim 1, wherein a link configuration initially associated with segments of said plurality of segments comprises a generally accepted non-optimized link configuration.

25. The method of claim 24, wherein said generally accepted non-optimized link configuration provides a substantially conventional sector configuration.

26. A system for optimizing a communication link, said system comprising:

a communication system having a service area associated therewith, wherein a plurality of segments are established within said service area;

a database storing link configuration information for a plurality of communication links, wherein communication links of said plurality of communication links are associated with corresponding segments of said plurality of segments;

a controller in communication with said communication system and said database, wherein said controller includes operating instructions to determine a segment of said service area a mobile unit is operating within, to identify link configuration information associated with said determined segment from available said link configuration information stored in said database, and to accept information with respect to said mobile unit operating within said determined segment using a link configured according to said identified link configuration information, wherein said controller further includes operating instructions to determine alternative link configuration information for use with said determined segment and to accept information with respect to said mobile unit operating within said determined segment using a link configured according to said alternative link configuration, and wherein said controller includes operating instructions to determine a current optimized link configuration from said accepted information with respect to said mobile unit operating using said identified link configuration information and said alternative link configuration information.

27. The system of claim 26, wherein said communication link is a forward link and said accepted information is provided through a corresponding reverse link.

28. The system of claim 26, wherein said communication system comprises:

an array antenna providing a plurality of antenna elements from which angle of arrival of a signal received from said mobile unit is determinable, wherein said determined segment is determined at least in part through reference to angle of arrival information derived from use of said array antenna.

29. The system of claim 28, wherein said communication system further comprises:

circuitry for determining signal delay associated with said mobile unit, wherein said determined segment is also determined at least in part through reference to said delay information.

30. The system of claim 26, wherein said communication system comprises a cellular base station, and wherein said service area comprises a cell of a cellular communication system.

31. The system of claim 30, wherein a size of said segments is selected at least in part through reference to a resolution of a location determination ability associated with said communication system.

32. The system of claim 31, wherein said segments are established in a grid arrangement throughout said cell.

33. The system of claim 26, wherein the link configuration information stored in the database comprises:

current link configuration information.

34. The system of claim 33, wherein said current link configuration information associated with at least one segment of said plurality of segments comprises an initial link configuration determined to provide a minimum level of system performance.

35. The system of claim 33, wherein said current link configuration information comprises a most current optimized link configuration for each segment of said plurality of segments.

36. The system of claim 33, wherein the link configuration information stored in the database further comprises:

historical link configuration information.

37. The system of claim 33, wherein said historical link configuration information comprises a previous link configuration associated with at least one segment of said plurality of segments which is has been implemented in the past for providing a communication link in the corresponding segment but which is not currently considered to be a most optimized link configuration.

38. The system of claim 37, wherein said previous link configuration provides a larger antenna beam than a corresponding current optimized link configuration.

39. The system of claim 37, wherein said previous link configuration provides a smaller antenna beam than a corresponding current optimized link configuration.

40. The system of claim 37, wherein said previous link configuration is stored in the database to provide a link configuration for use when a corresponding current optimized link configuration is determined to provide undesired attributes.

41. The system of claim 37, wherein said previous link configuration is stored in the database to provide a link configuration which should not be implemented in the future.

42. The system of claim 26, wherein said link configuration information comprises antenna beam forming attributes.

43. The system of claim 42, wherein said antenna beam forming attributes comprise an antenna beam width.

44. The system of claim 42, wherein said antenna beam forming attributes comprise an antenna beam length.

45. The system of claim 42, wherein said antenna beam forming attributes comprise an antenna beam orientation.

46. The system of claim 26, wherein said accepted information with respect to said mobile unit operating using said identified link configuration information and said alternative link configuration information comprises a set point.

47. The system of claim 46, wherein said accepted information with respect to said mobile unit operating using said identified link configuration information and said alternative link configuration information comprises a frame error rate.

48. The system of claim 46, wherein said accepted information with respect to said mobile unit operating using said identified link configuration information and said alternative link configuration information comprises a ratio of average bit energy to noise energy.

49. The system of claim 26, wherein said controller further includes operating instructions to limit an amount by which information with respect to said mobile unit affects said determination of a current optimized link configuration.

50. The system of claim 49, wherein said limit is established at least in part through a number of channel characteristic reports provided by said mobile unit.

51. The system of claim 49, wherein said controller further includes operating instructions to determine a link configuration for use with said mobile unit separate from said determined current optimized link configuration.

52. A system for optimizing a communication link, said system comprising:

means for demarcating a plurality of segments within a service area associated with a first communication system;

means for associating a unique link configuration with each segment of said plurality of segments;

means for implementing a control loop for a first segment of said plurality of segments when a remote communication system is operating therein, whereby a first link configuration of said unique link configurations associated with said first segment is adjusted as a function of link conditions experienced by said remote communication system, wherein said means for implementing a control loop for a first segment comprises;

means for determining a segment of said service area said first remote communication system is operable within;

means for identifying said first link configuration associated with said determined segment;

means for providing a communication link to said first remote communication system using said identified first link configuration;

means for monitoring a communication attribute of said communication link provided using said identified first link configuration;

means for determining an alternative link configuration for use with said determined segment;

means for providing a communication link to said first remote communication system using said alternative link configuration;

means for monitoring a communication attribute of said communication link provided using said alternative link configuration; and

means for determining a link configuration to use in providing a communication link in the future based at least in part on said communication attributes monitored with respect to said identified first link configuration and said alternative link configuration; and

means for implementing a control loop for a second segment of said plurality of segments when said remote communication system is operating therein, whereby a second link configuration of said unique link configurations associated with said second segment is adjusted as a function of link conditions experienced by said remote communication system.

53. The system of claim 52, wherein said service area comprises a cell of a cellular communication system.

54. The system of claim 53, wherein said first remote communication system comprises a cellular telephone handset.

55. The system of claim 54, further comprising:

means for determining a position of said first remote communication system.

56. The system of claim 55, wherein said means for determining comprises:

means for determining an angle of arrival of a signal associated with said first remote communication system; and

means for determining a distance to said first remote communication system.

57. The system of claim 52, wherein said unique link configurations comprise an antenna beam forming attribute.

58. The system of claim 52, wherein said monitored communication attribute comprises a frame error rate.

59. The system of claim 52, wherein said monitored communication attribute comprises a ratio of average bit energy to noise energy.

60. The system of claim 52, wherein said means for determining a link configuration to use comprises:

means for determining one of said identified first link configuration and said alternative link configuration to use in providing a communication link in the future.

61. The system of claim 52, wherein said means for implementing a control loop for a first segment comprises:

means for limiting an extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment.

62. The system of claim 61, wherein implementing a control loop for a first segment further comprises:

means for implementing a control loop for said remote communication system during a time in which the extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment are limited.

63. The system of claim 61, wherein said means for limiting an extent by which said link conditions experienced by said remote communication system result in adjusting said first link configuration associated with said first segment is provided at least in part through a determination of a number of link condition reports associated with said remote communication system.

64. A method for optimizing a forward link using a minimum amount of reverse link feedback, said method comprising:

dividing a service area associated with a first communication system into a plurality of segments;

storing a current communication link configuration associated with a first communication link channel for each segment of said plurality of segments; and

implementing a control loop optimizing a forward link for use in a first segment of said plurality of segments, wherein said control loop comprises;

determining that a second communication system is operating within said first segment;

retrieving a current communication link configuration for said first segment from said stored current communication link configurations;

utilizing said retrieved current communication link configuration in providing forward link communication between said first communication system and said second communication system;

monitoring a link channel attribute associated with said utilization of said retrieved current communication link configuration;

providing information feedback with respect to said monitored link channel attribute;

determining a next communication link configuration for said first segment;

utilizing said determined next communication link configuration in providing forward link communication between said first communication system and said second communication system;

monitoring a link channel attribute associated with said utilization of said determined next communication link configuration;

providing information feedback with respect to said monitored link channel attribute; and

determining a preferred one of said retrieved current communication link configuration and said determined next communication link configuration as a function of said information feedback associated with said retrieved current communication link configuration and said monitored link channel attribute associated with said determined next communication link configuration.

65. The method of claim 64, wherein said first communication system comprises a cellular base transceiver station, said second communication system comprises a subscriber communication unit, and said service area comprises a cell of a cellular communication system.

67. The method of claim 64, wherein said control loop further comprises:

limiting an extent by which said link channel attributes monitored by said second communication system affect the determination of a preferred one of said retrieved current communication link configuration and said determined next communication link configuration to thereby prevent domination of said determination by information associated with said second communication system.

66. The method of clam 64, further comprising:

implementing a control loop optimizing a forward link for use in a second segment of said plurality of segments, wherein said control loop comprises;

determining a that said second communication system is operating within said second segment;

retrieving a current communication link configuration for said second segment from said stored current communication link configurations;

utilizing said retrieved current communication link configuration in providing forward link communication between said first communication system and said second communication system;

monitoring a link channel attribute associated with said utilization of said retrieved current communication link configuration;

providing information feedback with respect to said monitored link channel attribute;

determining a next communication link configuration for said second segment;

utilizing said determined next communication link configuration in providing forward link communication between said first communication system and said second communication system;

monitoring a link channel attribute associated with said utilization of said determined next communication link configuration;

providing information feedback with respect to said monitored link channel attribute; and

determining a preferred one of said retrieved current communication link configuration and said determined next communication link configuration as a function of said information feedback associated with said retrieved current communication link configuration and said monitored link channel attribute associated with said determined next communication link configuration.