APERIODIC AND PERIODIC CSI FEEDBACK MODES FOR COORDINATED MULTI-POINT TRANSMISSION

• US 20130336214A1
• Filed: 06/18/2013
• Published: 12/19/2013
• Est. Priority Date: 06/18/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Sayana, Krishna, Ng, Boon Loong, Nam, Young-Han, Han, Jinkyu, Zhang, Jianzhong, Lee, Hyojin, Novlan, Thomas
• Granted Patent: US 11,121,834 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• 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 7/063 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 7/0647 Variable feedback rate
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04L 43/06 Generation of reports
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Coordinate multi-point (CoMP) transmission is facilitated by resolving collisions between feedback reporting. Based upon the conditions within the network, collision resolution may be by dropping a channel report during a subframe, multiplexing channel reports from a plurality of user equipment, compressing channel reports a plurality of user equipment, and combined reporting, either through joint reports or by using carrier aggregation, for conditions between a user equipment and a plurality of transmission points. New signaling and reporting formats facilitate selection of a collision resolution suitable for current network conditions.

Claims

1. A user equipment, comprising:

a control system configured to report channel state information (CSI) to one of a plurality of transmission points from which the user equipment is receiving signals,

wherein a rank indicator (RI) for the reported CSI is selected to correspond to an RI specified for a current RI-reference CSI process for the user equipment, and

wherein a format for the reported CSI is selected to be compatible with the selected RI.

2. The user equipment according to claim 1, wherein the reported CSI comprises CSI reference signal (CSI-RS) information.

3. The user equipment according to claim 1, wherein the selected RI is employed for CSI reporting by the user equipment to two or more of the transmission points.

4. The user equipment according to claim 1, wherein the reported CSI comprises a periodic CSI report.

5. The user equipment according to claim 1, wherein the reported CSI comprises an aperiodic CSI report.

6. A user equipment, comprising:

a control system configured

to report channel state information (CSI) to each of two or more transmission points from which the user equipment is receiving signals, and

in response to a collision between at least two CSI reports to different transmission points, to drop one of the at least two CSI reports based upon configuration indices associated with the two CSI reports.

7. The user equipment according to claim 6, wherein the one of the at least two CSI reports corresponding to a lowest serving cell configuration index is dropped.

8. The user equipment according to claim 6, wherein the one of the at least two CSI reports corresponding to a lowest CSI configuration index is dropped.

9. The user equipment according to claim 6, wherein all of the at least two CSI reports are dropped except for one of the at least two CSI reports corresponding to a lowest CSI configuration index.

10. The user equipment according to claim 6, wherein the reported CSI comprises a periodic CSI report.

11. A base station, comprising:

a control system configured to receive channel state information (CSI) reports from a user equipment reporting CSI to each of a plurality of transmission points from which the user equipment is receiving signals,

wherein a rank indicator (RI) for the reported CSI is selected to correspond to an RI specified for a current RI-reference CSI process for the user equipment, and

wherein a format for the reported CSI is selected to be compatible with the selected RI.

12. The base station according to claim 11, wherein the reported CSI comprises CSI reference signal (CSI-RS) information.

13. The base station according to claim 11, wherein the selected RI is employed for CSI reporting by the user equipment to two or more of the transmission points.

14. The base station according to claim 11, wherein the reported CSI comprises a periodic CSI report.

15. The base station according to claim 11, wherein the reported CSI comprises an aperiodic CSI report.

16. A base station, comprising:

a control system configured to receive channel state information (CSI) reports from a user equipment reporting CSI to each of two or more transmission points from which the user equipment is receiving signals,

wherein, in response to a collision between at least two CSI reports from the user equipment to different transmission points, a received one of the at least two CSI reports is based upon configuration indices associated with the two CSI reports.

17. The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest serving cell configuration index.

18. The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest of two CSI configuration indices associated with two CSI reports of the at least two CSI reports.

19. The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest of all CSI configuration indices associated with the at least two CSI reports.

20. The base station according to claim 16, wherein the reported CSI comprises a periodic CSI report.