METHOD AND APPARATUS FOR SUPPORTING SINGLE-USER MULTIPLE-INPUT MULTIPLE-OUTPUT (SU-MIMO) AND MULTI-USER MIMO (MU-MIMO)

• US 20110194504A1
• Filed: 08/11/2010
• Published: 08/11/2011
• Est. Priority Date: 08/12/2009
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei Yurievitch, Montojo, Juan, Chen, Wanshi
• Application Number:
  US12/854,431
• Publication Number:
  US 20110194504A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/0641 Differential feedback
• CPC Class Codes: H04B 7/0645 Variable feedback
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication

Abstract

Techniques for supporting data transmission with single-user multiple-input multiple-output (SU-MIMO) and multi-user MIMO (MU-MIMO) are described. A base station may transmit multiple data streams on a given time-frequency resource to a single user equipment (UE) for SU-MIMO or to multiple UEs for MU-MIMO. In an aspect, an antenna port assignment for a UE for MU-MIMO may be conveyed by reusing one or more fields of a downlink control information (DCI) format. In another aspect, a hierarchical two-tier structure may be used to convey an antenna port assignment for a UE for MU-MIMO. In yet another aspect, a UE may be configured via higher layer to report only channel quality indicator (CQI), or both CQI and precoding matrix indicator (PMI), when operating in a transmission mode supporting SU-MIMO and MU-MIMO. In yet another aspect, a UE may report CQI such that SU-MIMO and MU-MIMO can be supported for the UE.

Claims

1. A method for wireless communication, comprising:

scheduling a user equipment (UE) for data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO);

assigning an antenna port among a plurality of antenna ports to the UE;

generating a control message for the UE based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO; and

setting a designated field of the control message to convey the antenna port assigned to the UE, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

2. The method of claim 1, wherein the plurality of antenna ports comprise a first antenna port and a second antenna port, and wherein the designated field is set to a first value to indicate the first antenna port being assigned to the UE or to a second value to indicate the second antenna port being assigned to the UE.

3. The method of claim 1, wherein the designated field comprises a flag indicating an assignment of localized or distributed virtual resource blocks when the DCI format is used for the another transmission mode not supporting MU-MIMO.

4. An apparatus for wireless communication, comprising:

means for scheduling a user equipment (UE) for data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO);

means for assigning an antenna port among a plurality of antenna ports to the UE;

means for generating a control message for the UE based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO; and

means for setting a designated field of the control message to convey the antenna port assigned to the UE, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

5. The apparatus of claim 4, wherein the plurality of antenna ports comprise a first antenna port and a second antenna port, and wherein the designated field is set to a first value to indicate the first antenna port being assigned to the UE or to a second value to indicate the second antenna port being assigned to the UE.

6. The apparatus of claim 4, wherein the designated field comprises a flag indicating an assignment of localized or distributed virtual resource blocks when the DCI format is used for the another transmission mode not supporting MU-MIMO.

7. An apparatus for wireless communication, comprising:

at least one processor configured to schedule a user equipment (UE) for data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO), to assign an antenna port among a plurality of antenna ports to the UE, to generate a control message for the UE based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO, and to set a designated field of the control message to convey the antenna port assigned to the UE, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

8. A computer program product comprising a non-transitory computer-readable medium comprising instructions stored thereon, the instructions when executed cause at least one computer to:

schedule a user equipment (UE) for data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO);

assign an antenna port among a plurality of antenna ports to the UE;

generate a control message for the UE based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO; and

set a designated field of the control message to convey the antenna port assigned to the UE, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

9. A method for wireless communication, comprising:

receiving signaling configuring a user equipment (UE) with a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO);

receiving a control message sent to the UE and generated based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO; and

determining an antenna port assigned to the UE, from among a plurality of antenna ports, based on a designated field of the control message, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

10. The method of claim 9, wherein the plurality of antenna ports comprise a first antenna port and a second antenna port, and wherein the determining the antenna port assigned to the UE comprises:

determining that the first antenna port is assigned to the UE based on the designated field being set to a first value, and

determining that the second antenna port is assigned to the UE based on the designated field being set to a second value.

11. The method of claim 9, wherein the designated field comprises a flag indicating an assignment of localized or distributed virtual resource blocks when the DCI format is used for the another transmission mode not supporting MU-MIMO.

12. An apparatus for wireless communication, comprising:

means for receiving signaling configuring a user equipment (UE) with a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO);

means for receiving a control message sent to the UE and generated based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO; and

means for determining an antenna port assigned to the UE, from among a plurality of antenna ports, based on a designated field of the control message, the designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

13. The apparatus of claim 12, wherein the plurality of antenna ports comprise a first antenna port and a second antenna port, and wherein the means for determining the antenna port assigned to the UE comprises:

means for determining that the first antenna port is assigned to the UE based on the designated field being set to a first value, and

means for determining that the second antenna port is assigned to the UE based on the designated field being set to a second value.

14. The apparatus of claim 12, wherein the designated field comprises a flag indicating an assignment of localized or distributed virtual resource blocks when the DCI format is used for the another transmission mode not supporting MU-MIMO.

15. A method for wireless communication, comprising:

configuring a user equipment (UE) with a plurality of antenna port combinations corresponding to a subset of all possible antenna port combinations;

assigning an antenna port combination among the plurality of antenna port combinations to the UE for a data transmission; and

sending control information to convey the antenna port combination assigned to the UE.

16. The method of claim 15, wherein each antenna port combination is associated with at least one antenna to use for the data transmission among a plurality of available antenna ports.

17. The method of claim 15, wherein the UE is configured with the plurality of antenna port combinations via Layer 3, and wherein the control information is sent to the UE via Layer 2.

18. The method of claim 15, wherein the UE is semi-statically configured with the plurality of antenna port combinations, and wherein the UE is dynamically assigned one antenna port combination for each data transmission.

19. The method of claim 15, further comprising:

scheduling the UE for the data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO).

20. The method of claim 19, wherein the sending the control information comprises:

generating a control message for the UE based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO, and

setting at least one designated field of the control message to convey the antenna port combination assigned to the UE, the at least one designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

21. The method of claim 15, further comprising:

transmitting data via the antenna port combination assigned to the UE.

22. An apparatus for wireless communication, comprising:

means for configuring a user equipment (UE) with a plurality of antenna port combinations corresponding to a subset of all possible antenna port combinations;

means for assigning an antenna port combination among the plurality of antenna port combinations to the UE for a data transmission; and

means for sending control information to convey the antenna port combination assigned to the UE.

23. The apparatus of claim 22, wherein the UE is configured with the plurality of antenna port combinations via Layer 3, and wherein the control information is sent to the UE via Layer 2.

24. The apparatus of claim 22, wherein the UE is semi-statically configured with the plurality of antenna port combinations, and wherein the UE is dynamically assigned one antenna port combination for each data transmission.

25. A method for wireless communication, comprising:

receiving signaling configuring a user equipment (UE) with a plurality of antenna port combinations corresponding to a subset of all possible antenna port combinations; and

receiving control information assigning an antenna port combination among the plurality of antenna port combinations to the UE for a data transmission.

26. The method of claim 25, wherein the signaling configuring the UE is received via Layer 3, and wherein the control information assigning the antenna port combination to the UE is received via Layer 2.

27. The method of claim 25, wherein the UE is semi-statically configured with the plurality of antenna port combinations, and wherein the UE is dynamically assigned one antenna port combination for each data transmission.

28. The method of claim 25, wherein the UE is scheduled for the data transmission based on a transmission mode supporting multi-user multiple-input multiple-output (MU-MIMO).

29. The method of claim 28, wherein the receiving the control information comprises

receiving a control message sent to the UE and generated based on a downlink control information (DCI) format available for the transmission mode supporting MU-MIMO, and

determining the antenna port combination assigned to the UE based on at least one designated field of the control message, the at least one designated field conveying other information when the DCI format is used for another transmission mode not supporting MU-MIMO.

30. An apparatus for wireless communication, comprising:

means for receiving signaling configuring a user equipment (UE) with a plurality of antenna port combinations corresponding to a subset of all possible antenna port combinations; and

means for receiving control information assigning an antenna port combination among the plurality of antenna port combinations to the UE for a data transmission.

31. The apparatus of claim 30, wherein the signaling configuring the UE is received via Layer 3, and wherein the control information assigning the antenna port combination to the UE is received via Layer 2.

32. The apparatus of claim 30, wherein the UE is semi-statically configured with the plurality of antenna port combinations, and wherein the UE is dynamically assigned one antenna port combination for each data transmission.

33. A method for wireless communication, comprising:

configuring a user equipment (UE) to operate based on a transmission mode supporting single-user multiple-input multiple-output (SU-MIMO) and multi-user MIMO (MU-MIMO);

configuring the UE to report channel quality indicator (CQI) and to either report precoding matrix indicator (PMI) or not report PMI;

receiving CQI from the UE;

receiving PMI from the UE if configured to be reported by the UE; and

transmitting data to the UE based on the CQI and also the PMI if received from the UE.

34. The method of claim 33, further comprising:

configuring the UE to either report rank indicator (RI) or not report RI;

receiving RI from the UE if configured to be reported by the UE; and

transmitting data to the UE based further on the RI if received from the UE.

35. The method of claim 34, wherein the transmitting data comprises transmitting data based on a rank of one if the UE is configured to not report RI.

36. The method of claim 33, wherein the transmitting data comprises precoding data based on a precoding vector or matrix indicated by the PMI if received from the UE.

37. The method of claim 33, wherein the transmitting data comprises transmitting data with transmit diversity if the PMI is not received from the UE.

38. The method of claim 33, wherein the UE is semi-statically configured to report PMI or not report PMI via Layer 3.

39. An apparatus for wireless communication, comprising:

means for configuring a user equipment (UE) to operate based on a transmission mode supporting single-user multiple-input multiple-output (SU-MIMO) and multi-user MIMO (MU-MIMO);

means for configuring the UE to report channel quality indicator (CQI) and to either report precoding matrix indicator (PMI) or not report PMI;

means for receiving CQI from the UE;

means for receiving PMI from the UE if configured to be reported by the UE; and

means for transmitting data to the UE based on the CQI and also the PMI if received from the UE.

40. The apparatus of claim 39, further comprising:

means for configuring the UE to either report rank indicator (RI) or not report RI;

means for receiving RI from the UE if configured to be reported by the UE; and

means for transmitting data to the UE based further on the RI if received from the UE.

41. A method for wireless communication, comprising:

receiving signaling configuring a user equipment (UE) to operate based on a transmission mode supporting single-user multiple-input multiple-output (SU-MIMO) and multi-user MIMO (MU-MIMO);

receiving signaling configuring the UE to report channel quality indicator (CQI) and to either report precoding matrix indicator (PMI) or not report PMI;

sending CQI by the UE;

sending PMI by the UE if configured to be reported by the UE; and

receiving data transmitted to the UE based on the CQI and also the PMI if sent by the UE.

42. The method of claim 41, further comprising:

receiving signaling configuring the UE to either report rank indicator (RI) or not report RI;

sending RI by the UE if configured to be reported by the UE; and

receiving data transmitted to the UE based further on the RI if sent by the UE.

43. The method of claim 42, wherein the receiving data comprises receiving data transmitted based on a rank of one if the UE is configured to not report RI.

44. The method of claim 41, wherein the receiving data comprises receiving data precoded based on a precoding vector or matrix indicated by the PMI if sent by the UE.

45. The method of claim 41, wherein the receiving data comprises receiving data transmitted with transmit diversity if the PMI is not sent by the UE.

46. The method of claim 41, wherein the UE is semi-statically configured to report PMI or not report PMI via Layer 3.

47. An apparatus for wireless communication, comprising:

means for receiving signaling configuring a user equipment (UE) to operate based on a transmission mode supporting single-user multiple-input multiple-output (SU-MIMO) and multi-user MIMO (MU-MIMO);

means for receiving signaling configuring the UE to report channel quality indicator (CQI) and to either report precoding matrix indicator (PMI) or not report PMI;

means for sending CQI by the UE;

means for sending PMI by the UE if configured to be reported by the UE; and

means for receiving data transmitted to the UE based on the CQI and also the PMI if sent by the UE.

48. The apparatus of claim 47, further comprising:

means for receiving signaling configuring the UE to either report rank indicator (RI) or not report RI;

means for sending RI by the UE if configured to be reported by the UE; and

means for receiving data transmitted to the UE based further on the RI if sent by the UE.

49. A method for wireless communication, comprising:

receiving first channel quality indicator (CQI) determined by a user equipment (UE) for single-user multiple-input multiple-output (SU-MIMO);

receiving second CQI determined by the UE for multi-user MIMO (MU-MIMO);

scheduling the UE for data transmission based on SU-MIMO or MU-MIMO; and

transmitting data to the UE based on the first CQI if the UE is scheduled with SU-MIMO and based on the second CQI if the UE is scheduled with MU-MIMO.

50. The method of claim 49, wherein the first CQI comprises one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

51. The method of claim 49, wherein the second CQI comprises one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

52. The method of claim 49, wherein the second CQI comprises one differential CQI value for rank 1 or two differential CQI values for rank 2, and wherein each differential CQI value is determined based on the first CQI as a reference.

53. The method of claim 49, further comprising:

receiving a report comprising the first CQI and the second CQI.

54. The method of claim 49, further comprising:

receiving a first report comprising the first CQI; and

receiving a second report comprising the second CQI.

55. The method of claim 54, wherein the first and second reports are sent by the UE with time division multiplexing (TDM).

56. An apparatus for wireless communication, comprising:

means for receiving first channel quality indicator (CQI) determined by a user equipment (UE) for single-user multiple-input multiple-output (SU-MIMO);

means for receiving second CQI determined by the UE for multi-user MIMO (MU-MIMO);

means for scheduling the UE for data transmission based on SU-MIMO or MU-MIMO; and

means for transmitting data to the UE based on the first CQI if the UE is scheduled with SU-MIMO and based on the second CQI if the UE is scheduled with MU-MIMO.

57. The apparatus of claim 56, wherein the first CQI comprises one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

58. The apparatus of claim 56, wherein the second CQI comprises one differential CQI value for rank 1 or two differential CQI values for rank 2, and wherein each differential CQI value is determined based on the first CQI as a reference.

59. A method for wireless communication, comprising:

sending first channel quality indicator (CQI) determined by a user equipment (UE) for single-user multiple-input multiple-output (SU-MIMO);

sending second CQI determined by the UE for multi-user MIMO (MU-MIMO); and

receiving data transmitted to the UE based on the first CQI if the UE is scheduled with SU-MIMO and based on the second CQI if the UE is scheduled with MU-MIMO.

60. The method of claim 59, further comprising:

generating the first CQI comprising one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

61. The method of claim 59, further comprising:

generating the second CQI comprising one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

62. The method of claim 59, further comprising:

generating the second CQI comprising one differential CQI value for rank 1 or two differential CQI values for rank 2, wherein each differential CQI value is determined based on the first CQI as a reference.

63. The method of claim 59, further comprising:

sending a report comprising the first CQI and the second CQI.

64. The method of claim 59, further comprising:

sending a first report comprising the first CQI; and

sending a second report comprising the second CQI.

65. The method of claim 64, wherein the first and second reports are sent by the UE with time division multiplexing (TDM).

66. An apparatus for wireless communication, comprising:

means for sending first channel quality indicator (CQI) determined by a user equipment (UE) for single-user multiple-input multiple-output (SU-MIMO);

means for sending second CQI determined by the UE for multi-user MIMO (MU-MIMO); and

means for receiving data transmitted to the UE based on the first CQI if the UE is scheduled with SU-MIMO and based on the second CQI if the UE is scheduled with MU-MIMO.

67. The apparatus of claim 66, further comprising:

means for generating the first CQI comprising one absolute CQI value for rank 1, or one absolute CQI value and one differential CQI value for rank 2.

68. The apparatus of claim 66, further comprising:

means for generating the second CQI comprising one differential CQI value for rank 1 or two differential CQI values for rank 2, wherein each differential CQI value is determined based on the first CQI as a reference.