Mechanism for providing channel feedback in multi-cell communication

Patent metadata

Field	Value
Publication number	US-9380592-B2
Application number	US-201013993352-A
Country	US
Kind code	B2
Filing date	Dec 13, 2010
Priority date	Dec 13, 2010
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

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.

First claim

The invention claimed is:

1. An apparatus, comprising:
at least one processor; and
at least one memory including computer program code, where the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to at least:
identify a joint set of communication subbands by jointly considering transmissions over a plurality of cells with which a user equipment can perform a communication,
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 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
joint information comprising a joint quality indicator related to a simultaneous transmission using all cells, over the joint set of communication subbands; and

transmit the status report to control nodes of each of the plurality of cells for use to perform the communication over one or more of the plurality of cells.

2. The apparatus according to claim 1 , wherein the at least one memory including the computer program code is configured with the at least one processor to cause the apparatus to identify the joint set of communication subbands of the plurality of cells with which the user equipment can perform the communication 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
those subbands of all subbands of the plurality of cells providing a specific minimum communication quality level.

4. The apparatus according to claim 1 , wherein the at least one memory including the computer program code is configured with the at least one processor to cause the apparatus to determine for at least one of the cell specific information and the joint information one of:
a channel quality indication for a first codeword and a delta channel quality indication for a second codeword, and
a channel quality indicator for each of a first and second codeword.

5. The apparatus according to claim 1 , wherein the at least one memory including the computer program code is configured with the at least one processor to cause the apparatus to determine and include in the status report at least one of:
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 at least one memory including the computer program code is configured with the at least one processor to cause the apparatus 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, by a user equipment, a joint set of communication subbands by jointly considering transmission over a plurality of cells with which the user equipment can perform a communication,
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

generating, by the user equipment, a status report, wherein the status report comprises 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
joint information comprising a joint quality indicator related to a transmission using all cells; and

transmitting, by the user equipment, the status report to control nodes of each of the plurality of cells for use to perform the communication over one or more 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
those subbands of all subbands of the plurality of cells providing a specific minimum communication quality level.

11. The method according to claim 8 , wherein the generation of the status report further comprises one of:
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, and
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:
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

Assignees

• Lunttila Timo Erkki
• Pedersen Klaus Ingemann
• Nokia Solutions & Networks Oy

Inventors

• Lunttila Timo Erkki
• Pedersen Klaus Ingemann

Classifications

• H04W72/542 Primary

  using measured or perceived quality · CPC title

• H04W72/085 Primary

  Electricity · mapped topic

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04W24/10

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04L5/0035

  Resource allocation in a cooperative multipoint environment · CPC title