CSI feedback for data transmission over multiple transmission points

Patent metadata

Field	Value
Publication number	US-12052199-B2
Application number	US-201917290858-A
Country	US
Kind code	B2
Filing date	Nov 1, 2019
Priority date	Nov 2, 2018
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

Systems and methods for Channel State Information (CSI) feedback for multiple Transmission Points (TRPs) in a cellular communications network are disclosed. Embodiments of a method of operation of a wireless device and corresponding embodiments of a wireless device are disclosed. In some embodiments, a method performed by a wireless device for CSI feedback comprises receiving a configuration comprising N Non-Zero Power (NZP) CSI Reference Signal (CSI-RS) resources each associated with a different one of N TRPs or N sets of NZP CSI-RS resources each associated with a different one of the N TRPs. The method further comprises receiving a request for CSI feedback based on the configuration, selecting a preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources, and reporting, to a base station, CSI based on the selected preferred subset of the NZP CSI-RS resources.

First claim

What is claimed is:

1. A method performed by a wireless device for Channel State Information, CSI, feedback, the method comprising:
receiving a configuration comprising:
N Non-Zero Power, NZP, CSI Reference Signal, CSI-RS, resources or N sets of NZP CSI-RS resources; and
a size M of a to-be-selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources;

receiving a request for CSI feedback based on the configuration;
selecting the preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources; and
reporting, to a base station, CSI based on the selected preferred subset of the NZP CSI-RS resources.

2. The method of claim 1 wherein M<N.

3. The method of claim 2 wherein N≥2.

4. The method of claim 2 wherein N≥3, and M≥1.

5. The method of claim 2 wherein N≥3, and M≥2.

6. The method of claim 1 , wherein the CSI comprises an identity of each NZP CSI-RS resource in the selected preferred subset.

7. The method of claim 6 wherein, for each NZP CSI-RS resource in the selected preferred subset, the identity of the NZP CSI-RS resource is an index of the NZP CSI-RS resource within a set of NZP CSI-RS resources configured for the wireless device.

8. The method of claim 1 , further comprising receiving an indication of a restriction from the base station.

9. The method of claim 1 , wherein the selected preferred subset corresponds to a preferred subset of the N TRPs for a downlink transmission to the wireless device, wherein the downlink transmission is one of Non-Coherent Joint Transmission, NC-JT, a Dynamic Point Selection, DPS, transmission, or a diversity combining transmission.

10. The method of claim 1 , wherein the selected preferred subset is for any one or any combination of NC-JT, DPS, and diversity combining.

11. The method of claim 1 , wherein reporting the CSI comprises sending a CSI report comprising a first part and a second part, wherein a size of the selected preferred subset is encoded in the first part.

12. The method of claim 11 , wherein the first part has a predefined payload size, is encoded before encoding the second part at the wireless device, or both has a predefined payload size and is encoded before encoding the second part at the wireless device.

13. The method of claim 12 , wherein some part of the CSI is dropped from the second part of the CSI report.

14. The method of claim 11 , wherein the first part is decoded first at the base station.

15. The method of claim 1 wherein:
receiving the configuration comprises receiving two or more CSI reporting configurations, each for one transmission mode with Non-Coherent Joint Transmission, NC-JT, a Dynamic Point Selection, DPS, or diversity combining; and
receiving the request for CSI feedback comprises receiving a request for CSI feedback of two or more CSI reports.

16. The method of claim 1 , wherein reporting the CSI comprises reporting:
a common CSI component comprising a rank associated with each of the NZP CSI-RS resources in the selected preferred subset;
a common CSI component comprising precoding matrix indicators for each of the NZP CSI-RS resources in the selected preferred subset; and
two or more Channel Quality Indicators, CQIs, each for a different transmission mode.

17. A method performed by a base station for Channel State Information, CSI, feedback for Physical Downlink Shared Channel, PDSCH, transmission in a wireless network, the method comprising:
providing, to a wireless device, a configuration comprising:
N Non-Zero Power, NZP, CSI Reference Signal, CSI-RS, resources or N sets of NZP CSI-RS resources; and
a size M of a to-be-selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources;

requesting a CSI feedback from the wireless device based on the configuration; and
receiving, from the wireless device, CSI based on the selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources.

18. A wireless device for Channel State Information, CSI, feedback, the wireless device comprising:
one or more transmitters;
one or more receivers; and
processing circuitry associated with the one or more transmitters and the one or more receivers, the processing circuitry configured to cause the wireless device to:
receive a configuration comprising:
N Non-Zero Power, NZP, CSI Reference Signal, CSI-RS, resources or N sets of NZP CSI-RS resources; and
a size M of a to-be-selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources;

receive a request for CSI feedback based on the configuration;
select the preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources; and
report, to a base station, CSI based on the selected preferred subset of the NZP CSI-RS resources.

19. A base station for Channel State Information, CSI, feedback, the base station comprising:
processing circuitry configured to cause the base station to:
provide, to a wireless device, a configuration comprising:
N Non-Zero Power, NZP, CSI Reference Signal, CSI-RS, resources or N sets of NZP CSI-RS resources; and
a size M of a to-be-selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources;

request a CSI feedback from the wireless device based on the configuration; and
receive, from the wireless device, CSI based on a selected preferred subset of the NZP CSI-RS resources comprised in the N NZP CSI-RS resources or the N sets of NZP CSI-RS resources.

Assignees

• Ericsson Telefon Ab L M

Inventors

• Gao Shiwei
• Muruganathan Siva
• Faxér Sebastian
• Frenne Mattias
• Järmyr Simon

Classifications

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04L5/0091

  Signalling for the administration of the divided path, e.g. signalling of configuration information · CPC title

• H04L5/005 Primary

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title

• H04L5/0035

  Resource allocation in a cooperative multipoint environment · CPC title

• H04L5/0057 Primary

  Physical resource allocation for CQI · CPC title