POWER CONTROL AND USER MULTIPLEXING FOR HETEROGENEOUS NETWORK COORDINATED MULTIPOINT OPERATIONS

• US 20120236741A1
• Filed: 02/13/2012
• Published: 09/20/2012
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Luo, Xiliang, Zhang, Xiaoxia, Gaal, Peter, Ji, Tingfang, Montojo, Juan
• Granted Patent: US 10,187,859 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Certain aspects of the present disclosure relate to techniques for power control and user multiplexing for coordinated multi-point (CoMP) transmission and reception in heterogeneous networks (HetNet).

Claims

1. A method for wireless communications by a user equipment (UE), comprising:

measuring channel state information reference signals (CSI-RS) transmitted from at least one of a set of transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

open loop power control based on the measured CSI-RS from at least one of the transmission points.

2. The method of claim 1, wherein performing open loop power control based on the measured CSI-RS from at least one of the set of transmission points comprises:

performing open loop power control based on the strongest measured CSI-RS.

3. The method of claim 1, wherein the CSI-RS transmitted from each of the set of transmission points is different.

4. The method of claim 3, wherein a common cell ID is used for each of the set of transmission points.

5. The method of claim 1, further comprising receiving signaling indicating at least one of location or power spectrum density (PSD) of CSI-RS for each of the set of transmission points.

6. The method of claim 5, wherein the signaling is conveyed in a system information block (SIB).

7. An apparatus for wireless communications, comprising:

means for measuring channel state information reference signals (CSI-RS) transmitted from at least one of a set of transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

means for performing open loop power control based on the measured CSI-RS from at least one of the transmission points.

8. The apparatus of claim 7, wherein the means for performing open loop power control based on the measured CSI-RS from at least one of the set of transmission points is configured to:

perform open loop power control based on the strongest measured CSI-RS.

9. The apparatus of claim 7, wherein the CSI-RS transmitted from each of the set of transmission points is different.

10. The apparatus of claim 9, wherein a common cell ID is used for each of the set of transmission points.

11. The apparatus of claim 7, further comprising means for receiving signaling indicating at least one of location or power spectrum density (PSD) of CSI-RS for each of the set of transmission points.

12. The apparatus of claim 11, wherein the signaling is conveyed in a system information block (SIB).

13. An apparatus for wireless communications, comprising:

at least one processor configured to;

measure channel state information reference signals (CSI-RS) transmitted from at least one of a set of transmission points involved in coordinated multipoint (CoMP) operations with a UE; and

perform open loop power control based on the measured CSI-RS from at least one of the transmission points; and

a memory coupled to the at least one processor.

14. A computer-program product for wireless communications, comprising:

a computer-readable medium having code for;

measuring channel state information reference signals (CSI-RS) transmitted from at least one of a set of transmission points involved in coordinated multipoint (CoMP) operations with a UE; and

performing open loop power control based on the measured CSI-RS from at least one of the transmission points.

15. A method for wireless communications by a base station, comprising:

determining one or more parameters for use by a user equipment (UE) in open loop (OL) power control, wherein the one or more parameters are determined to take into account coordinated multipoint (CoMP) operations; and

signaling the one or more parameters to the UE.

16. The method of claim 15, wherein the CoMP operations comprise different DL transmission points and UL reception points.

17. The method of claim 15, wherein at least one of the one or more parameters comprises a parameter representing a target power received at the base station for a random access channel (RACH) that is set to a low value to allow low initial transmit power of the RACH.

18. The method of claim 15, wherein the one or more parameters are determined to adjust open loop power control based on differences between path loss between the UE and one or more transmission points involved in downlink (DL) CoMP operations and one or more transmission points involved in uplink (UL) CoMP operations.

19. The method of claim 15, wherein the one or more parameters are determined to take into account at least one of UL macro diversity gain or joint processing gain.

20. The method of claim 15, wherein the one or more parameters comprise a parameter that represents path loss difference between DL and UL serving nodes.

21. An apparatus for wireless communications, comprising:

means for determining one or more parameters for use by a user equipment (UE) in open loop (OL) power control, wherein the one or more parameters are determined to take into account coordinated multipoint (CoMP) operations; and

means for signaling the one or more parameters to the UE.

22. The apparatus of claim 21, wherein the CoMP operations comprise different DL transmission points and UL reception points.

23. The apparatus of claim 21, wherein at least one of the one or more parameters comprises a parameter representing a target power received at the base station for a random access channel (RACH) that is set to a low value to allow low initial transmit power of the RACH.

24. The apparatus of claim 21, wherein the one or more parameters are determined to adjust open loop power control based on differences between path loss between the UE and one or more transmission points involved in downlink (DL) CoMP operations and one or more transmission points involved in uplink (UL) CoMP operations.

25. The apparatus of claim 21, wherein the one or more parameters are determined to take into account at least one of UL macro diversity gain or joint processing gain.

26. The apparatus of claim 21, wherein the one or more parameters comprise a parameter that represents path loss difference between DL and UL serving nodes.

27. An apparatus for wireless communications, comprising:

at least one processor configured to;

determine one or more parameters for use by a user equipment (UE) in open loop (OL) power control, wherein the one or more parameters are determined to take into account coordinated multipoint (CoMP) operations; and

signal the one or more parameters to the UE; and

a memory coupled to the at least one processor.

28. A computer-program product for wireless communications, comprising:

a computer-readable medium comprising code for;

determining one or more parameters for use by a user equipment (UE) in open loop (OL) power control, wherein the one or more parameters are determined to take into account coordinated multipoint (CoMP) operations; and

signaling the one or more parameters to the UE.

29. A method for wireless communications by a base station, comprising:

receiving a transmission from a UE; and

determining one or more cells to include in a coordinated multipoint (CoMP) group, based on the received transmission

30. The method of claim 29, wherein:

the transmission comprises a sounding reference signal (SRS); and

the determination is made based on received signal strength of the SRS at different cells.

31. The method of claim 30, wherein cells with the strongest receive signal strength are included in the CoMP group.

32. The method of claim 29, wherein the transmission comprises feedback from the UE indicating cells to include in the CoMP group, wherein the UE selects the indicated cells based on channel state information reference signals (CSI-RS) transmitted from multiple cells.

33. The method of claim 32, wherein the feedback also indicates cells to include in a downlink (DL) CoMP group.

34. The method of claim 29, wherein the transmission comprises feedback from the UE indicating path loss (PL) from a plurality of cells, wherein the PL for each cell is calculated based on channel state information reference signals (CSI-RS) transmitted from the plurality of cells.

35. The method of claim 34, wherein differences in transmit power for different cells is considered when determining cells to include in the CoMP group.

36. An apparatus for wireless communications, comprising:

means for receiving a transmission from a UE; and

means for determining one or more cells to include in a coordinated multipoint (CoMP) group, based on the received transmission.

37. The apparatus of claim 36, wherein:

the transmission comprises a sounding reference signal (SRS); and

the determination is made based on received signal strength of the SRS at different cells.

38. The apparatus of claim 37, wherein cells with the strongest receive signal strength are included in the CoMP group.

39. The apparatus of claim 36, wherein the transmission comprises feedback from the UE indicating cells to include in the CoMP group, wherein the UE selects the indicated cells based on channel state information reference signals (CSI-RS) transmitted from multiple cells.

40. The apparatus of claim 39, wherein the feedback also indicates cells to include in a downlink (DL) CoMP group.

41. The apparatus of claim 36, wherein the transmission comprises feedback from the UE indicating path loss (PL) from a plurality of cells, wherein the PL for each cell is calculated based on channel state information reference signals (CSI-RS) transmitted from the plurality of cells.

42. The apparatus of claim 41, wherein differences in transmit power for different cells is considered when determining cells to include in the CoMP group.

43. An apparatus for wireless communications, comprising:

at least one processor configured to;

receive a transmission from a UE; and

determine one or more cells to include in a coordinated multipoint (CoMP) group, based on the received transmission; and

a memory coupled to the at least one processor.

44. A computer-program product for wireless communications, comprising:

a computer-readable medium comprising code for;

receiving a transmission from a UE; and

determining one or more cells to include in a coordinated multipoint (CoMP) group, based on the received transmission.

45. A method for wireless communications by a user equipment, comprising:

receiving distinct channel state information reference signals (CSI-RS) transmitted from a plurality of cells; and

transmitting feedback, based on the received CSI-RS, that may be used to determine one or more cells to include in an uplink (UL) coordinated multipoint (CoMP) group.

46. The method of claim 45, wherein the feedback indicates cells to include in the UL CoMP group.

47. The method of claim 46, wherein the feedback also indicates cells to include in a downlink (DL) CoMP group.

48. The method of claim 45, wherein the feedback indicates path loss (PL) from the plurality of cells.

49. An apparatus for wireless communications, comprising:

means for receiving distinct channel state information reference signals (CSI-RS) transmitted from a plurality of cells; and

means for transmitting feedback, based on the received CSI-RS, that may be used to determine one or more cells to include in an uplink (UL) coordinated multipoint (CoMP) group.

50. The apparatus of claim 49, wherein the feedback indicates cells to include in the UL CoMP group.

51. The apparatus of claim 50, wherein the feedback also indicates cells to include in a downlink (DL) CoMP group.

52. The apparatus of claim 49, wherein the feedback indicates path loss (PL) from the plurality of cells.

53. An apparatus for wireless communications, comprising:

at least one processor configured to;

receive distinct channel state information reference signals (CSI-RS) transmitted from a plurality of cells; and

transmit feedback, based on the received CSI-RS, that may be used to determine one or more cells to include in an uplink (UL) coordinated multipoint (CoMP) group; and

a memory coupled to the at least one processor.

54. A computer-program product for wireless communications by a user equipment, comprising:

a computer-readable medium comprising code for;

receiving distinct channel state information reference signals (CSI-RS) transmitted from a plurality of cells; and

transmitting feedback, based on the received CSI-RS, that may be used to determine one or more cells to include in an uplink (UL) coordinated multipoint (CoMP) group.

55. A method for wireless communication by a base station (BS), comprising:

determining a channel state information reference signal (CSI-RS), the CSI-RS being different from CSI-RS transmitted by one or more other transmission points sharing a common physical cell identifier (PCI) with the base station, the CSI-RS being decoupled from the PCI; and

transmitting the CSI-RS from the base station.

56. The method of claim 55, wherein the configuration comprises at least a CSI-RS sequence and a frequency location.

57. An apparatus for wireless communication, comprising:

means for determining a channel state information reference signal (CSI-RS), the CSI-RS being different from CSI-RS transmitted by one or more other transmission points sharing a common physical cell identifier (PCI) with the base station, the CSI-RS being decoupled from the PCI; and

means for transmitting the CSI-RS from the base station.

58. The apparatus of claim 57, wherein the configuration comprises at least a CSI-RS sequence and a frequency location.

59. An apparatus for wireless communication, comprising:

at least one processor configured to;

determine a channel state information reference signal (CSI-RS), the CSI-RS being different from CSI-RS transmitted by one or more other transmission points sharing a common physical cell identifier (PCI) with the base station, the CSI-RS being decoupled from the PCI; and

transmit the CSI-RS from the base station; and

a memory coupled to the at least one processor.

60. A computer-program product for wireless communication, comprising:

a computer-readable medium comprising code for;

determining a channel state information reference signal (CSI-RS), the CSI-RS being different from CSI-RS transmitted by one or more other transmission points sharing a common physical cell identifier (PCI) with the base station, the CSI-RS being decoupled from the PCI; and

transmitting the CSI-RS from the base station.

61. A method for wireless communication by a user equipment (UE), comprising:

transmitting a sounding reference signal (SRS) from the UE in proximity to a plurality of transmission points sharing a common physical cell identifier (PCI);

receiving, from at least one of the transmission points, information regarding configuration for uplink coordinated multipoint (UL CoMP) operation, the configuration being decoupled from the PCI.

62. The method of claim 61, wherein the configuration for the SRS comprises at least a root sequence, a cyclic shift, a frequency location and a comb.

63. An apparatus for wireless communication, comprising:

means for transmitting a sounding reference signal (SRS) from a UE in proximity to a plurality of transmission points sharing a common physical cell identifier (PCI);

means for receiving, from at least one of the transmission points, information regarding configuration for uplink coordinated multipoint (UL CoMP) operation, the configuration being decoupled from the PCI.

64. The apparatus of claim 63, wherein the configuration for the SRS comprises at least a root sequence, a cyclic shift, a frequency location and a comb.

65. An apparatus for wireless communication, comprising:

at least one processor configured to;

transmit a sounding reference signal (SRS) from the UE in proximity to a plurality of transmission points sharing a common physical cell identifier (PCI);

receive, from at least one of the transmission points, information regarding

configuration for uplink coordinated multipoint (UL CoMP) operation, the configuration being decoupled from the PCI; and

a memory coupled to the at least one processor.

66. A computer-program product for wireless communication, comprising:

computer-readable medium comprising code for;

transmitting a sounding reference signal (SRS) from the UE in proximity to a plurality of transmission points sharing a common physical cell identifier (PCI);

receiving, from at least one of the transmission points, information regarding configuration for uplink coordinated multipoint (UL CoMP) operation, the configuration being decoupled from the PCI.

67. A method for wireless communications by a transmission point involved in coordinated multipoint (CoMP) operations, comprising:

signaling one or more UEs regarding a channel quality indication (CQI) configuration for CQI transmission, wherein the signaled CQI configuration is decoupled from physical cell identifier (PCI) of the transmission point.

68. The method of claim 67, wherein the transmission point shares a common PCI with one or more other transmission points involved in the CoMP operations.

69. An apparatus for wireless communications involved in coordinated multipoint (CoMP) operations, comprising:

means for signaling one or more UEs regarding a channel quality indication (CQI) configuration for CQI transmission, wherein the signaled CQI configuration is decoupled from physical cell identifier (PCI) of the transmission point.

70. The apparatus of claim 69, wherein the transmission point shares a common PCI with one or more other transmission points involved in the CoMP operations.

71. An apparatus for wireless communications involved in coordinated multipoint (CoMP) operations, comprising:

at least one processor configured to;

signal one or more UEs regarding a channel quality indication (CQI) configuration for CQI transmission, wherein the signaled CQI configuration is decoupled from physical cell identifier (PCI) of the transmission point; and

a memory coupled to the at least one processor.

72. A computer-program product for wireless communications by a transmission point involved in coordinated multipoint (CoMP) operations, comprising:

a computer-readable medium comprising code for;

signaling one or more UEs regarding a channel quality indication (CQI) configuration for CQI transmission, wherein the signaled CQI configuration is decoupled from physical cell identifier (PCI) of the transmission point.

73. A method for wireless communications by a user equipment (UE), comprising:

receiving a physical uplink control channel (PUCCH) configuration from a first transmission point participating in coordinated multipoint (CoMP) operations with one or more other transmission points;

transmitting a PUCCH to a first set of one or more transmission points in accordance with the PUCCH configuration; and

transmitting a physical uplink shared channel (PUSCH) to a second set of one or more transmission points different than the first set of transmission points.

74. An apparatus for wireless communications, comprising:

means for receiving a physical uplink control channel (PUCCH) configuration from a first transmission point participating in coordinated multipoint (CoMP) operations with one or more other transmission points;

means for transmitting a PUCCH to a first set of one or more transmission points in accordance with the PUCCH configuration; and

means for transmitting a physical uplink shared channel (PUSCH) to a second set of one or more transmission points different than the first set of transmission points.

75. An apparatus for wireless communications by a user equipment (UE), comprising:

at least one processor configured to;

receive a physical uplink control channel (PUCCH) configuration from a first transmission point participating in coordinated multipoint (CoMP) operations with one or more other transmission points;

transmit a PUCCH to a first set of one or more transmission points in accordance with the PUCCH configuration; and

transmit a physical uplink shared channel (PUSCH) to a second set of one or more transmission points different than the first set of transmission points; and

a memory coupled to the at least one processor.

76. A computer-program product for wireless communications by a user equipment (UE), comprising:

a computer-readable medium comprising code for;

receiving a physical uplink control channel (PUCCH) configuration from a first transmission point participating in coordinated multipoint (CoMP) operations with one or more other transmission points;

transmitting a PUCCH to a first set of one or more transmission points in accordance with the PUCCH configuration; and

transmitting a physical uplink shared channel (PUSCH) to a second set of one or more transmission points different than the first set of transmission points.

77. A method for wireless communications by a user equipment (UE), comprising:

generating channel quality indication (CQI) information for downlink transmission from a first set of one or more transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

sending the CQI information to a second set of transmission points involved in CoMP operations with the UE.

78. An apparatus for wireless communications, comprising:

means for generating channel quality indication (CQI) information for downlink transmission from a first set of one or more transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

means for sending the CQI information to a second set of transmission points involved in CoMP operations with the UE.

79. An apparatus for wireless communications, comprising:

at least one processor configured to;

generate channel quality indication (CQI) information for downlink transmission from a first set of one or more transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

send the CQI information to a second set of transmission points involved in CoMP operations with the UE; and

a memory coupled to the at least one processor.

80. A computer-program product for wireless communications, comprising:

a computer-readable medium comprising code for;

generating channel quality indication (CQI) information for downlink transmission from a first set of one or more transmission points involved in coordinated multipoint (CoMP) operations with the UE; and

sending the CQI information to a second set of transmission points involved in CoMP operations with the UE.