METHOD AND APPARATUS THAT FACILITATES A TIMING ALIGNMENT IN A MULTICARRIER SYSTEM

• US 20110158116A1
• Filed: 06/17/2010
• Published: 06/30/2011
• Est. Priority Date: 06/19/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi, Tenny, Nathan Edward, Agashe, Parag Arun, Gaal, Peter, Ji, Tingfang, Prakash, Rajat
• Granted Patent: US 8,634,313 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time

Abstract

Aspects are disclosed for facilitating a timing alignment in a multicarrier system. In one aspect, at least one downlink timing associated with at least one downlink carrier is determined, and an uplink timing associated with an uplink group of carriers is ascertained based on at least one downlink timing and a timing offset associated with the uplink group of carriers. Each of the uplink group of carriers is then transmitted within a threshold value of the uplink timing. In another aspect, a downlink communication is transmitted to a wireless terminal via at least one downlink carrier. This embodiment further includes assigning a timing offset to an uplink group of carriers, and providing the timing offset to the wireless terminal via the at least one downlink carrier. An uplink communication is then received via the uplink group of carriers according to the timing offset.

Claims

1. A method that facilitates a timing alignment in a multicarrier system, the method comprising:

determining at least one downlink timing associated with at least one downlink carrier;

ascertaining an uplink timing associated with an uplink group of carriers, wherein the uplink timing is ascertained based on a processing of at least one downlink timing and a timing offset associated with the uplink group of carriers; and

transmitting each of the uplink group of carriers within a threshold value of the uplink timing.

2. The method of claim 1, further comprising performing a random access procedure on at least one random access carrier, wherein the at least one random access carrier is included in a downlink group of carriers that includes the at least one downlink carrier.

3. The method of claim 2, wherein the performing comprises performing the random access procedure on a single carrier.

4. The method of claim 3, wherein the single carrier is an assigned carrier provided by a network prior to the performing of the random access procedure.

5. The method of claim 4, further comprising receiving the single carrier as part of a dedicated radio resource configuration.

6. The method of claim 4, further comprising receiving a criterion associated with a usage of the single carrier, wherein the criterion is received with an assignment of the single carrier.

7. The method of claim 6, wherein the criterion is a minimum signal quality threshold associated with the single carrier.

8. The method of claim 6, wherein the performing comprises performing the random access procedure on an alternative carrier in response to the criterion not being met by the single carrier, and wherein the receiving further comprises receiving an indication of the alternative carrier from the network.

9. The method of claim 6, wherein the performing comprises performing the random access procedure on an alternative carrier in response to the criterion not being met by the single carrier, and wherein the alternative carrier is independently selected by a wireless terminal.

10. The method of claim 3, further comprising selecting the single carrier, wherein the single carrier is independently selected by a wireless terminal.

11. The method of claim 10, wherein the selecting comprises applying a determination function across a set of available carriers in the downlink group of carriers.

12. The method of claim 11, wherein the determination function is a pseudorandom function.

13. The method of claim 11, wherein the determination function is a hash function.

14. The method of claim 13, further comprising inputting an identifier associated with the wireless terminal into the hash function.

15. The method of claim 13, further comprising inputting an identifier associated with a network node into the hash function, wherein the downlink group of carriers is controlled by the network node.

16. The method of claim 13, further comprising inputting a time-varying value into the hash function.

17. The method of claim 16, further comprising determining the time-varying value via a time measurement taken from within the wireless terminal.

18. The method of claim 16, further comprising modifying the time-varying value by an arithmetic operation each time the time-varying value is used.

19. The method of claim 10, wherein the selecting is performed at a time when radio resources are assigned to the wireless terminal on any of the downlink group of carriers.

20. The method of claim 10, wherein the selecting is performed in response to a triggering of the random access procedure.

21. An apparatus configured to facilitate a timing alignment in a multicarrier system, the apparatus comprising:

a processor configured to execute computer executable components stored in memory, the components including;

a downlink timing component configured to determine at least one downlink timing associated with at least one downlink carrier;

an uplink timing component configured to ascertain an uplink timing associated with an uplink group of carriers, wherein the uplink timing is ascertained based on at least one downlink timing and a timing offset associated with the uplink group of carriers; and

a communication component configured to transmit each of the uplink group of carriers within a threshold value of the uplink timing.

22. The apparatus of claim 21, wherein the uplink timing component is configured to determine the uplink timing by utilizing a different timing offset for each of a plurality of uplink group of carriers.

23. The apparatus of claim 21, wherein the uplink timing component is configured to determine the uplink timing by utilizing a different downlink timing for each of a plurality of uplink group of carriers.

24. The apparatus of claim 21, wherein the at least one downlink carrier is included in one of a plurality of downlink groups, and wherein the uplink timing component is configured to determine the uplink timing by associating the uplink group of carriers with the one of the plurality of downlink groups.

25. The apparatus of claim 24, wherein the uplink timing component is configured to determine a plurality of uplink timings respectively associated with a plurality of uplink groups by identifying a subset of downlink groups that include an assigned carrier, and wherein the plurality of uplink groups are respectively associated with the subset of downlink groups that include the assigned carrier.

26. The apparatus of claim 24, further comprising a message processing component configured to process a received timing message encoded with a set of uplink timing instructions respectively corresponding to an uplink group subset of the uplink group of carriers.

27. The apparatus of claim 26, wherein the received timing message is a timing advance command.

28. The apparatus of claim 26, wherein the received timing message comprises a vector encoded with timing adjustment values associated with the uplink group subset.

29. The apparatus of claim 26, wherein each uplink group within the uplink group subset includes at least one carrier with an assigned radio resource.

30. The apparatus of claim 26, wherein the uplink group of carriers comprise a set of uplink groups in which each uplink group within the set of uplink groups includes at least one carrier with an assigned radio resource, and wherein the uplink group subset is a subset of the set of uplink groups.

31. The apparatus of claim 30, wherein the uplink group subset is determined by a network entity.

32. The apparatus of claim 31, wherein the message processing component is configured to submit a request requesting the network entity to provide the uplink group subset, and wherein the uplink group subset is determined by the network entity in response to the request.

33. The apparatus of claim 30, wherein the received timing message includes an indication of which of the uplink group of carriers are included in the uplink group subset.

34. The apparatus of claim 33, wherein the message processing component is configured to decode the indication according to a mapping of group identities shared with a network.

35. The apparatus of claim 34, wherein the mapping of group identities is configured in association with an assignment of dedicated radio resources on uplink carriers within at least one uplink group of the uplink group subset.

36. The apparatus of claim 24, further comprising a message processing component configured to decode a timing message received via a timing message carrier included in a messenger downlink group, wherein the timing message is encoded with at least one inter-group uplink timing corresponding to a target downlink group, and wherein the target downlink group is different than the messenger downlink group.

37. The apparatus of claim 36, wherein the timing message includes an indication of the target downlink group.

38. The apparatus of claim 37, wherein the message processing component configured to decode the indication according to a mapping of group identities shared with a network.

39. The apparatus of claim 38, wherein the mapping of group identities is configured in association with an assignment of dedicated radio resources on downlink carriers included in the target downlink group.

40. The apparatus of claim 21, further comprising an averaging component configured to compute an average downlink timing from a plurality of downlink timings respectively corresponding to a set of downlink carriers within a particular downlink group that includes the at least one downlink carrier, wherein the uplink timing component is configured to determine the uplink timing by applying the timing offset to the average downlink timing.

41. The apparatus of claim 40, wherein the particular downlink group comprises at least one carrier associated with an assigned radio resource.

42. The apparatus of claim 40, wherein the particular downlink group comprises a set of carriers identified by a network.

43. A computer program product that facilitates a timing alignment in a multicarrier system, comprising:

a computer-readable storage medium comprising code for causing at least one computer to;

determine at least one downlink timing associated with at least one downlink carrier;

ascertain an uplink timing associated with an uplink group of carriers, wherein the uplink timing is ascertained based on at least one downlink timing and a timing offset associated with the uplink group of carriers; and

transmit each of the uplink group of carriers within a threshold value of the uplink timing.

44. The computer program product of claim 43, wherein the code causes the at least one computer to associate the uplink group of carriers with one of a plurality of downlink groups, and wherein the code further causes the at least one computer to receive a timing message encoded with a set of uplink timing instructions respectively corresponding to a downlink group subset of the plurality of downlink groups.

45. The computer program product of claim 43, wherein the code causes the at least one computer to decode a timing message received via a timing message carrier included in a messenger downlink group, and wherein the timing message is encoded with at least one inter-group uplink timing corresponding to a target downlink group different than the messenger downlink group.

46. The computer program product of claim 43, wherein the code causes the at least one computer to compute an average downlink timing from a plurality of downlink timings respectively corresponding to a set of downlink carriers within a particular downlink group that includes the at least one downlink carrier, and wherein the code further causes the at least one computer to determine the uplink timing by applying the timing offset to the average downlink timing.

47. The computer program product of claim 43, wherein the code causes the at least one computer to perform a random access procedure on at least one random access carrier, and wherein the at least one random access carrier is included in a downlink group of carriers that includes the at least one downlink carrier.

48. An apparatus configured to facilitate a timing alignment in a multicarrier system, the apparatus comprising:

means for determining at least one downlink timing associated with at least one downlink carrier;

means for ascertaining an uplink timing associated with an uplink group of carriers, wherein the uplink timing is ascertained based on at least one downlink timing and a timing offset associated with the uplink group of carriers; and

means for transmitting each of the uplink group of carriers within a threshold value of the uplink timing.

49. The apparatus of claim 48, wherein the means for ascertaining is configured to utilize a different timing offset for each of a plurality of uplink group of carriers.

50. The apparatus of claim 48, wherein the means for ascertaining is configured to utilize a different downlink timing for each of a plurality of uplink group of carriers.

51. The apparatus of claim 48, wherein the at least one downlink carrier is included in one of a plurality of downlink groups, and wherein the means for ascertaining is configured to associate the uplink group of carriers with the one of the plurality of downlink groups.

52. The apparatus of claim 48, further comprising means for performing a random access procedure on at least one random access carrier, wherein the at least one random access carrier is included in a downlink group of carriers that includes the at least one downlink carrier.

53. A method that facilitates a timing alignment in a multicarrier system, the method comprising:

transmitting a downlink communication to a wireless terminal via at least one downlink carrier;

assigning a timing offset to an uplink group of carriers;

providing the timing offset to the wireless terminal via the at least one downlink carrier; and

receiving an uplink communication via the uplink group of carriers, wherein the uplink group of carriers are received according to the timing offset.

54. The method of claim 53, wherein the assigning comprises assigning a different timing offset to each of a plurality of uplink groups.

55. The method of claim 54, further comprising generating a timing message encoded with a set of uplink timing instructions respectively corresponding to an uplink group subset of the plurality of uplink groups, wherein the transmitting comprises transmitting the timing message to the wireless terminal.

56. The method of claim 55, wherein the timing message is a timing advance command.

57. The method of claim 55, wherein the timing message comprises a vector encoded with timing adjustment values associated with the uplink group subset.

58. The method of claim 55, wherein each uplink group within the uplink group subset includes at least one carrier with a radio resource assigned to the wireless terminal.

59. The method of claim 55, wherein the plurality of uplink groups comprise a set of uplink groups in which each uplink group within the set of uplink groups includes at least one carrier with a radio resource assigned to the wireless terminal, and wherein the uplink group subset is a subset of the set of uplink groups.

60. The method of claim 59, further comprising determining the uplink group subset.

61. The method of claim 60, further comprising receiving a request from the wireless terminal to provide the uplink group subset, wherein the determining is performed in response to the request.

62. The method of claim 59, wherein the timing message is encoded with an indication of which of the plurality of uplink groups are included in the uplink group subset.

63. The method of claim 62, wherein the indication is encoded according to a mapping of group identities shared with the wireless terminal.

64. The method of claim 63, wherein the mapping of group identities is configured in association with an assignment of dedicated radio resources on uplink carriers within at least one uplink group of the uplink group subset.

65. The method of claim 54, further comprising generating a timing message encoded with at least one inter-group uplink timing corresponding to a target downlink group, wherein the transmitting comprises transmitting the timing message to the wireless terminal via a timing message carrier included in a messenger downlink group, and wherein the target downlink group is different than the messenger downlink group.

66. The method of claim 65, wherein the timing message is encoded with an indication of the target downlink group.

67. The method of claim 66, wherein the indication is encoded according to a mapping of group identities shared with the wireless terminal.

68. The method of claim 67, wherein the mapping of group identities is configured in association with an assignment of dedicated radio resources on downlink carriers included in the target downlink group.

69. An apparatus configured to facilitate a timing alignment in a multicarrier system, the apparatus comprising:

a processor configured to execute computer executable components stored in memory, the components including;

a timing offset component configured to assign a timing offset to an uplink group of carriers;

a transmitting component configured to provide the timing offset to a wireless terminal via at least one downlink carrier; and

a receiving component configured to receive an uplink communication via the uplink group of carriers, wherein the uplink group of carriers are received according to the timing offset.

70. The apparatus of claim 69, wherein the transmitting component is configured to transmit a downlink group of carriers from antennas located at a common site.

71. The apparatus of claim 69, wherein the transmitting component is configured to identify a set of carriers respectively corresponding to a plurality of downlink timings to facilitate an averaging of the plurality of downlink timings performed by the wireless terminal.

72. The apparatus of claim 69, further comprising a random access component configured to identify a random access carrier to facilitate a random access procedure, wherein the random access carrier is a carrier assigned to the wireless terminal.

73. The apparatus of claim 72, wherein the transmitting component is configured to transmit the random access carrier as part of a dedicated radio resource configuration.

74. The apparatus of claim 72, wherein the random access component is configured to ascertain a criterion associated with a usage of the random access carrier, and wherein the criterion is provided to the wireless terminal with an assignment of the random access carrier.

75. The apparatus of claim 74, wherein the criterion is a minimum signal quality threshold associated with the random access carrier.

76. The apparatus of claim 74, wherein the random access component is configured to identify an alternative carrier to facilitate a performing of the random access procedure by the wireless terminal on the alternative carrier in response to the criterion not being met by the random access carrier.

77. A computer program product that facilitates a timing alignment in a multicarrier system, comprising:

a computer-readable storage medium comprising code for causing at least one computer to;

transmit at least one downlink carrier to a wireless terminal;

assign a timing offset to an uplink group of carriers;

provide the timing offset to the wireless terminal via the at least one downlink carrier; and

receive an uplink communication via the uplink group of carriers, wherein the uplink group of carriers are received according to the timing offset.

78. The computer program product of claim 77, wherein the code causes the at least one computer to transmit a downlink group of carriers from antennas located at a common site.

79. The computer program product of claim 77, wherein the code causes the at least one computer to assign a different timing offset to each of a plurality of uplink groups.

80. The computer program product of claim 79, wherein the code causes the at least one computer to generate a timing message encoded with a set of uplink timing instructions respectively corresponding to an uplink group subset of the plurality of uplink groups, and wherein the code further causes the at least one computer to transmit the timing message to the wireless terminal.

81. The computer program product of claim 77, wherein the code causes the at least one computer to identify a set of carriers respectively corresponding to a plurality of downlink timings to facilitate an averaging of the plurality of downlink timings performed by the wireless terminal.

82. The computer program product of claim 77, wherein the code causes the at least one computer to identify a random access carrier to facilitate a random access procedure, and wherein the random access carrier is a carrier assigned to the wireless terminal.

83. An apparatus configured to facilitate a timing alignment in a multicarrier system, the apparatus comprising:

means for transmitting at least one downlink carrier to a wireless terminal;

means for assigning a timing offset to an uplink group of carriers;

means for providing the timing offset to the wireless terminal via the at least one downlink carrier; and

means for receiving an uplink communication via the uplink group of carriers, wherein the uplink group of carriers are received according to the timing offset.

84. The apparatus of claim 83, wherein the means for transmitting is configured to transmit a downlink group of carriers from antennas located at a common site.

85. The apparatus of claim 83, wherein the means for assigning is configured to assign a different timing offset to each of a plurality of uplink groups.

86. The apparatus of claim 85, further comprising a means for generating a timing message encoded with at least one inter-group uplink timing corresponding to a target downlink group, wherein the means for transmitting is configured to transmit the timing message to the wireless terminal via a timing message carrier included in a messenger downlink group, and wherein the target downlink group is different than the messenger downlink group.

87. The apparatus of claim 83, wherein the means for transmitting is configured to identify a set of carriers respectively corresponding to a plurality of downlink timings to facilitate an averaging of the plurality of downlink timings performed by the wireless terminal.

88. The apparatus of claim 83, wherein the means for transmitting is configured to identify a random access carrier to facilitate a random access procedure, and wherein the random access carrier is a carrier assigned to the wireless terminal.