USER EQUIPMENT

• US 20140126408A1
• Filed: 05/23/2012
• Published: 05/08/2014
• Est. Priority Date: 06/29/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ding, Ming, Huang, Lei, Yang, Zeng, Luo, Yuan
• Granted Patent: US 9,491,647 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 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A Channel State Information (CSI) feedback method and a User Equipment (UE) are provided for better support of Joint Transmission (JT) and Beamforming/Coordinated Scheduling (CB/CS). For JT, phase information for an adjacent Base Station (BS) is fed back. For CB/CS, enhanced CSI for an adjacent BS is fed back. The UE according to the present invention includes: a coordinated BS set determining unit configured for determining a set of coordinated BSs participating in multi-BS coordination, the set of coordinated BSs containing a serving BS and at least one non-serving BS; and a CSI feedback unit configured for feeding back CSI for JT or CB/CS for each non-serving BS in the set of coordinated BSs. The present invention has the advantages of simple implementation and low overhead and is applicable in LTE-A and 4G systems.

Claims

1. A User Equipment (UE), comprising:

a coordinated Base Station (BS) set determining unit configured for determining a set of coordinated BSs participating in multi-BS coordination, the set of coordinated BSs containing a serving BS and at least one non-serving BS; and

a Channel State Information (CSI) feedback unit configured for feeding back CSI for Joint Transmission (JT) or Coordinated Beamforming/Coordinated Scheduling (CB/CS) for each non-serving BS in the set of coordinated BSs.

2. The UE according to claim 1, wherein the CSI feedback unit is configured for indicating whether the fed back CSI is for JT or for CB/CS by using a Coordinated Multi-Point (CoMP) Type Indicator (CTI) in the CSI fed back to each non-serving BS.

3. The UE according to claim 1, wherein the CSI feedback unit is configured for determining whether to feed back CSI for JT or for CB/CS based on a system parameter configured by the serving BS in a semi-static manner via high layer signaling or MAC signaling.

4. The UE according to claim 2, wherein the CSI feedback unit is configured for including the CTI in a feedback Type 5 to form a new feedback Type 5 in Sub-Mode 1 of feedback Mode 1-1, and feeding back different CSI in Sub-Mode 1 of feedback Mode 1-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

10. The UE according to claim 3, wherein the CSI feedback unit is configured for feeding back different CSI in Sub-Mode 1 of feedback Mode 1-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

11. The UE according to claim 10, wherein the CSI feedback unit is configured for:

feeding back RI and W1 in the feedback Type 5;

or

feeding back RI and eW1 in the new feedback Type 5

when the CSI to be fed back is for CB/CS.

12. The UE according to claim 11, wherein eW1 is obtained by increasing the down-sampled set of W1.

17. The UE according to claim 4, wherein the CSI feedback unit is configured for forming a new feedback Type 2b and feeding back wideband eW2 and wideband CQI in the new feedback Type 2b when the CSI to be fed back is for CB/CS.

18. The UE according to claim 17, wherein the wideband eW2 is obtained by increasing the number of elements in a value range of the wideband W2.

21. The UE according to claim 2, wherein the CSI feedback unit is configured for including the CTI in a feedback Type 3 to form a new feedback Type 3 in Sub-Mode 2 of feedback Mode 1-1, and feeding back different CSI in Sub-Mode 2 of feedback Mode 1-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

25. The UE according to claim 3, wherein the CSI feedback unit is configured for feeding back different CSI in Sub-Mode 2 of feedback Mode 1-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

30. The UE according to claim 21, wherein the CSI feedback unit is configured for forming a new feedback Type 2c and feeding back wideband CQI, eW1 and wideband eW2 in the new feedback Type 2c when the CSI to be fed back is for CB/CS.

31. The UE according to claim 30, wherein eW1 is obtained by increasing the down-sampled set of W1 and the wideband eW2 is obtained by increasing the down-sampled set of wideband W2.

34. The UE according to claim 2, wherein the CSI feedback unit is configured for including the CTI in a feedback Type 6 to form a new feedback Type 6 in feedback Mode 2-1, and feeding back different CSI in the feedback Mode 2-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

38. The UE according to claim 3, wherein the CSI feedback unit is configured for feeding back different CSI in the feedback Mode 2-1 depending on whether the CSI to be fed back is for JT or for CB/CS.

52. The UE according to claim 34, wherein the CSI feedback unit is configured for forming a new feedback Type 2b and feeding back wideband eW2 and wideband CQI in the new feedback Type 2b when the CSI to be fed back is for CB/CS.

53. The UE according to claim 52, wherein the wideband eW2 is obtained by increasing the number of elements in a value range of the wideband W2.

57. The UE according to claim 1, wherein the CSI feedback unit is configured for feed back CSI for the serving BS.

58. The UE according to claim 1, wherein

the coordinated BS determining unit is configured for determining the non-serving BS based on a notification from the serving BS;

or

the coordinated BS determining unit is configured for determining the non-serving BS autonomously.

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