MITIGATION OF CRS MISALIGNMENT IN COORDINATED MULTIPOINT COMMUNICATIONS

• US 20110032838A1
• Filed: 08/03/2010
• Published: 02/10/2011
• Est. Priority Date: 08/04/2009
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Liu, Ke, Malladi, Durga Prasad, Zhang, Xiaoxia
• Application Number:
  US12/849,602
• Publication Number:
  US 20110032838A1
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path

Abstract

Certain aspects of the present disclosure relate to a method for coordinated multipoint wireless communications. A technique for joint processing of misaligned reference signals in coordinated multipoint communications is provided. In one aspect, a cell may transmit an offsetting reference signal which, when processed by a receiving user equipment, at least partially cancels a first reference signal transmitted by the cell.

Claims

1. A method for wireless communications, comprising:

transmitting a reference signal in a first group of tones;

transmitting an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

transmitting data in a third group of tones.

2. The method of claim 1, wherein the transmitting comprises transmitting in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

3. The method of claim 1, further comprising generating the offsetting reference signal based at least in part on the reference signal.

4. The method of claim 1, further comprising:

generating a composite signal comprising the offsetting reference signal and a data signal; and

transmitting the composite signal in the second group of tones.

5. The method of claim 4, wherein transmitting the composite signal comprises transmitting the data signal within a same symbol period as the offsetting reference signal.

6. The method of claim 1, wherein the groups of tones comprise a resource block group.

7. The method of claim 1, wherein frequency resources of the first group of tones are determined by a cell identity.

8. A method for wireless communications, comprising:

receiving a reference signal in a first group of tones; and

receiving an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

receiving data in a third group of tones.

9. The method of claim 8, wherein the groups of tones comprise a resource block group.

10. The method of claim 8, wherein the receiving comprises receiving the first, second, and third groups of tones from access points in a coordinated multi-point (CoMP) transmission.

11. The method of claim 8, wherein frequency resources of the first group of tones are determined by a cell identity.

12. The method of claim 8, wherein the offsetting reference signal is combined with the reference signal using linear processing.

13. The method of claim 8, wherein receiving the offsetting reference signal comprises receiving a composite signal including a data signal with the offsetting reference signal.

14. The method of claim 13, wherein receiving the composite signal further comprises receiving the data signal in a same symbol period as the offsetting reference signal.

15. The method of claim 8, further comprising receiving an indication of an offsetting reference signal pattern.

16. The method of claim 15, further comprising estimating channel quality based on the received offsetting reference signal and the indication of the offsetting reference signal pattern.

17. The method of claim 15, further comprising processing the reference signal and the offsetting reference signal based on the indication of the offsetting reference signal pattern.

18. An apparatus for wireless communications, comprising:

means for transmitting a reference signal in a first group of tones;

means for transmitting an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

means for transmitting data in a third group of tones.

19. The apparatus of claim 18, wherein the groups of tones comprise a resource block group.

20. The apparatus of claim 18, wherein the means for transmitting comprises means for transmitting in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

21. The apparatus of claim 18, wherein the first group of tones is determined by a cell identity.

22. The apparatus of claim 18, further comprising means for generating the offsetting reference signal based at least in part on the reference signal.

23. The apparatus of claim 18, further comprising:

means for generating a composite signal comprising the offsetting reference signal and a data signal; and

means for transmitting the composite signal in the second group of tones.

24. The apparatus of claim 23, wherein the means for transmitting the composite signal comprises means for transmitting the data signal within a same symbol period as the offsetting reference signal.

25. An apparatus for wireless communications, comprising:

means for receiving a reference signal in a first group of tones; and

means for receiving an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

means for receiving data in a third group of tones.

26. The apparatus of claim 25, wherein the groups of tones comprise a resource block group.

27. The apparatus of claim 25, wherein the means for receiving comprises means for receiving the first, second, and third groups of tones from access points in a coordinated multi-point (CoMP) transmission.

28. The apparatus of claim 25, wherein frequency resources of the first group of tones are determined by a cell identity.

29. The apparatus of claim 25, further comprising means for combining the offsetting reference signal with the reference signal using linear processing.

30. The apparatus of claim 25, wherein means for receiving the offsetting reference signal comprises means for receiving a composite signal including a data signal with the offsetting reference signal.

31. The apparatus of claim 30, wherein means for receiving the composite signal further comprises means for receiving the data signal within same symbol period as the offsetting reference signal.

32. The apparatus of claim 25, further comprising means for receiving an indication of an offsetting reference signal pattern.

33. The apparatus of claim 32, further comprising means for estimating channel quality based on the received offsetting reference signal and the indication of the offsetting reference signal pattern.

34. The apparatus of claim 32, further comprising means for processing the reference signal and the offsetting reference signal based on the indication of the offsetting reference signal pattern.

35. An apparatus for wireless communications, comprising:

an RS module configured to generate a reference signal;

an offset module configured to generate an offsetting reference signal suitable for at least partially cancelling the reference signal when combined with the reference signal; and

a transmitter configured to transmit the reference signal in a first group of tones, to transmit the offsetting reference signal in a second group of tones, and to transmit data in a third group of tones.

36. The apparatus of claim 35, wherein the groups of tones comprise a resource block group.

37. The apparatus of claim 35, wherein the transmitter is further configured to transmit the groups of tones in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

38. The apparatus of claim 35, wherein the first group of tones is determined by a cell identity of the apparatus.

39. The apparatus of claim 35, wherein the offset module is configured to generate symbols for the offsetting reference signal based at least in part on corresponding symbols of the reference signal.

40. The apparatus of claim 35, wherein the offset module is configured to generate a composite signal comprising the offsetting reference signal and a data signal, and wherein the transmitter is further configured to transmit the composite signal in the second group of tones.

41. The apparatus of claim 40, wherein the transmitter is further configured to transmit the composite signal such that the data signal is transmitted within a same symbol period as the offsetting reference signal.

42. An apparatus for wireless communications, comprising:

a receiver configured to receive a reference signal in a first group of tones; and

to receive an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

wherein the receiver is further configured to receive data in a third group of tones.

43. The apparatus of claim 42, wherein the groups of tones comprise a resource block group.

44. The apparatus of claim 42, wherein the receiver is further configured to receive the first, second, and third groups of tones from a access points in a coordinated multi-point (CoMP) transmission.

45. The apparatus of claim 42, wherein frequency resources of the first group of tones are determined by a cell identity.

46. The apparatus of claim 42, wherein the receiver is configured to combine the offsetting reference signal with the reference signal using linear processing.

47. The apparatus of claim 42, wherein the receiver is configured to receive a composite signal including a data signal with the offsetting reference signal.

48. The apparatus of claim 47, wherein the receiver is further configured to receive the composite signal including the data signal and the offsetting reference signal in a same symbol period.

49. The apparatus of claim 42, wherein the receiver is configured to receive an indication of an offsetting reference signal pattern.

50. The apparatus of claim 49, further comprising a channel estimation module configured to estimate channel quality based on the received offsetting reference signal and the indication of the offsetting reference signal pattern.

51. The apparatus of claim 49, further comprising a linear processing module configured to process the reference signal and the offsetting reference signal based on the indication of the offsetting reference signal pattern.

52. An apparatus for wireless communications, comprising:

at least one processor configured to cause the apparatus to;

transmit a reference signal in a first group of tones,

transmit an offsetting reference signal in a second group of tones,

wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal, and

transmit data in a third group of tones; and

a memory coupled to the at least one processor.

53. The apparatus of claim 52, wherein the groups of tones comprise a resource block group.

54. The apparatus of claim 52, wherein the at least one processor is configured to cause the apparatus to transmit in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

55. The apparatus of claim 52, wherein the first group of tones is determined by a cell identity of the wireless communication apparatus.

56. The apparatus of claim 52, wherein the at least one processor is further configured to generate the offsetting reference signal based at least in part on the reference signal.

57. The apparatus of claim 52, wherein the at least one processor is configured to generate a composite signal comprising the offsetting reference signal and a data signal, and wherein the composite signal is transmitted in the second group of tones.

58. The apparatus of claim 57, wherein at least one processor is configured to cause the apparatus to transmit the composite signal such that the data signal is transmitted in a same symbol period as the offsetting reference signal.

59. An apparatus for wireless communications, comprising:

at least one processor configured to cause the apparatus to;

receive a reference signal in a first group of tones,

receive an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal, and

receive data in a third group of tones; and

a memory coupled to the at least one processor.

60. The apparatus of claim 59, wherein the groups of tones comprise a resource block group.

61. The apparatus of claim 59, wherein the at least one processor is configured to cause the apparatus to receive the first, second, and third groups of tones in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

62. The apparatus of claim 59, wherein frequency resources of the first group of tones are determined by a cell identity.

63. The apparatus of claim 59, wherein the at least one processor is configured to combine the offsetting reference signal with the reference signal using linear processing.

64. The apparatus of claim 59, wherein the apparatus is configured to receive a composite signal including a data signal with the offsetting reference signal.

65. The apparatus of claim 64, wherein the at least one processor configured to obtain information relating to the data signal and the offsetting reference signal within a same symbol period of the composite signal.

66. The apparatus of claim 59, wherein the at least one processor is further configured to obtain an indication of an offsetting reference signal pattern.

67. The apparatus of claim 66, wherein the at least one processor is further configured to estimate channel quality based on the received offsetting reference signal and the indication of the offsetting reference signal pattern.

68. The apparatus of claim 66, wherein the at least one processor is further configured to process the reference signal and the offsetting reference signal based on the indication of the offsetting reference signal pattern.

69. A computer-program product for wireless communications, the computer-program product comprising a computer-readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising code for:

transmitting a reference signal in a first group of tones;

transmitting an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

transmitting data in a third group of tones.

70. The computer-program product of claim 69, wherein the groups of tones comprise a resource block group.

71. The computer-program product of claim 69, wherein the code for transmitting further comprises code for transmitting in time and frequency resources associated with a coordinated multi-point (CoMP) transmission.

72. The computer-program product of claim 69, wherein the first group of tones is determined by a cell identity.

73. The computer-program product of claim 69, wherein the code further comprises code for generating the offsetting reference signal based at least in part on the reference signal.

74. The computer-program product of claim 69, wherein the code further comprises:

code for generating a composite signal comprising the offsetting reference signal and a data signal; and

code for transmitting the composite signal in the second group of tones.

75. The computer-program product of claim 74, wherein the code for transmitting the composite signal further comprises code for transmitting the data signal within a same symbol period as the offsetting reference signal.

76. A computer-program product for wireless communications, the computer-program product comprising a computer-readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising code for:

receiving a reference signal in a first group of tones; and

receiving an offsetting reference signal in a second group of tones, wherein the offsetting reference signal is suitable for at least partially cancelling the reference signal when combined with the reference signal; and

receiving data in a third group of tones.

77. The computer-program product of claim 76, wherein the groups of tones comprise a resource block group.

78. The computer-program product of claim 76, wherein the code for receiving further comprises code for receiving the first, second, and third groups of tones from access points in a coordinated multi-point (CoMP) transmission.

79. The computer-program product of claim 76, wherein the first group of tones is determined by a cell identity.

80. The computer-program product of claim 76, further comprising code for combining the offsetting reference signal with the reference signal.

81. The computer-program product of claim 76, wherein code for receiving the offsetting reference signal further comprises code for receiving a composite signal including a data signal with the offsetting reference signal.

82. The computer-program product of claim 81, wherein the code for receiving the composite signal further comprises code for receiving the data signal within a same symbol period as the offsetting reference signal.

83. The computer-program product of claim 76, wherein the code further comprises code for receiving an indication of an offsetting reference signal pattern.

84. The computer-program product of claim 83, wherein the code further comprises code for estimating channel quality based on the received offsetting reference signal and the indication of the offsetting reference signal pattern.

85. The computer-program product of claim 83, wherein the code further comprises code for processing the reference signal and the offsetting reference signal based on the indication of the offsetting reference signal pattern.