Mechanism for Providing Channel Feedback in Multi-Cell Communication

• US 20130273931A1
• Filed: 12/13/2010
• Published: 10/17/2013
• Est. Priority Date: 12/13/2010
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Lunttila, Timo Erkki, Pedersen, Klaus Ingemann
• Granted Patent: US 9,380,592 B2
• Time in Patent Office: Days
• US Class Current: 455/452.2
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

There is proposed a mechanism allowing a compressed multi-cell channel state information feedback. In a user equipment communicating with plural base stations such as eNBs, a joint set of communication subbands is identified which includes those subbands which provide a specific communication quality level, and which are common to at least two of the plural cells. Then, a status report is generated and transmitted to the control nodes of each of the plural cells. The status report includes an information regarding the joint set of communication subbands, cell specific information including quality indicators for each cell of the plurality of cells related to a transmission using the subbands of the respective cell included in the joint set of communication subbands and quality indicators for each cell of the plurality of cells related to a transmission using all subbands of the respective cell, and joint information concerning a joint quality indicator related to a transmission using all cells.

Claims

1. Apparatus comprising

a first processor configured to identify a joint set of communication subbands of a plurality of cells with which a user equipment can communicate,

wherein the joint set of communication subbands includes those subbands which provide a specific communication quality level, and which are common to at least two of the plurality of cells, and

a second processor configured to generate a status report and initiate a transmission of the status report to control nodes of each of the plurality of cells,

wherein the status report comprises

an information regarding the joint set of communication subbands, and at least one of

cell specific information comprising a first quality indicator for each cell of the plurality of cells related to a transmission using the subbands of the respective cell included in the joint set of communication subbands, and a second quality indicator for each cell of the plurality of cells related to a transmission using all subbands of the respective cell, and/or

joint information comprising a joint quality indicator related to a transmission using all cells.

2. The apparatus according to claim 1, wherein the first processor configured to identify the joint set of communication subbands of the plurality of cells with which the user equipment can communicate is further configured

to detect in each subband of each of the plurality of cells at least one transmission quality parameter, and

to determine on the basis of the detected transmission quality parameter those subbands which provide the specific communication quality level.

3. The apparatus according to claim 1, wherein the specific communication quality level is based on at least one of

a predetermined number M of subbands from all subbands of the plurality of cells, wherein M>

0, providing the relatively best communication quality level compared to the remaining subbands, and/or

those subbands of all subbands of the plurality of subbands providing a specific minimum communication quality level.

4. The apparatus according to claim 1, wherein the second processor configured to generate the status report is further configured to determine for the cell specific information and/or the joint information

a channel quality indication for a first codeword and a delta channel quality indication for a second codeword, or

a channel quality indicator for each of a first and second codeword.

5. The apparatus according to claim 1, wherein the second processor configured to generate the status report is further configured to determine and include in the status report at least one of the following parameters:

a first precoding matrix indication for each cell of the plurality of cells related to a transmission using the subbands of the respective cell included in the joint set of communication subbands,

a second precoding matrix indication for each cell of the plurality of cells related to a transmission using all subbands of the respective cell,

a third precoding matrix indication considering a joint transmission from all cells,

a rank indicator for each cooperating cell, and

a rank indicator considering a joint transmission from all cells.

6. The apparatus according to claim 1, wherein the second processor configured to generate the status report is further configured to introduce in the status report as the information regarding the joint set of communication subbands one of a joint bitmap, a label or a combinatorial index indicating the subbands included in the joint set of communication subbands.

7. The apparatus according to claim 1, wherein the apparatus is implemented in a user equipment configured to communicate with each of the plurality of cells.

8. A method comprising

identifying a joint set of communication subbands of a plurality of cells with which a user equipment can communicate,

wherein the joint set of communication subbands includes those subbands which provide a specific communication quality level, and which are common to at least two of the plurality of cells, and generate a status report, wherein the status report comprises

an information regarding the joint set of communication subbands, and at least one of

cell specific information comprising a first quality indicator for each cell of the plurality of cells related to a transmission using the subbands of the respective cell included in the joint set of communication subbands, and a second quality indicator for each cell of the plurality of cells related to a transmission using all subbands of the respective cell, and/or

joint information comprising a joint quality indicator related to a transmission using all cells, and

initiating a transmission of the status report to control nodes of each of the plurality of cells.

9. The method according to claim 8, wherein the identification of the joint set of communication subbands of the plurality of cells with which the user equipment can communicate further comprises

detecting in each subband of each of the plurality of cells at least one transmission quality parameter, and

determining on the basis of the detected transmission quality parameter those subbands which provide the specific communication quality level.

10. The method according to claim 8, wherein the specific communication quality level is based on at least one of

a predetermined number M of subbands from all subbands of the plurality of cells, wherein M>

0, providing the relatively best communication quality level compared to the remaining subbands, and/or

those subbands of all subbands of the plurality of subbands providing a specific minimum communication quality level.

11. The method according to claims 8, wherein the generation of the status report further comprises

determining for the cell specific information and/or the joint information

a channel quality indication for a first codeword and a delta channel quality indication for a second codeword, or

a channel quality indication for each of a first and second codeword.

12. The method according to claim 8, wherein the generation of the status report further comprises

determining and including in the status report at least one of the following parameters:

a first precoding matrix indication for each cell of the plurality of cells related to a transmission using the subbands of the respective cell included in the joint set of communication subbands,

a second precoding matrix indication for each cell of the plurality of cells related to a transmission using all subbands of the respective cell,

a third precoding matrix indication considering a joint transmission from all cells,

a rank indicator for each cooperating cell, and

a rank indicator considering a joint transmission from all cells.

13. The method according to claim 8, wherein the generation of the status report further comprises

introducing in the status report as the information regarding the joint set of communication subbands one of a joint bitmap, a label or a combinatorial index indicating the subbands included in the joint set of communication subbands.

14. The method according to claim 8, wherein the method is executed in a user equipment configured to communicate with each of the plurality of cells.

15. A computer program product for a computer, comprising software code portions for performing the steps of claim 8, when said product is run on the computer.

16. A computer program product according to claim 15,

wherein said computer program product comprises a computer-readable medium on which said software code portions are stored, and/or

wherein said computer program product is directly loadable into the internal memory of the computer by means of at least one of upload, download and push procedures.