Downlink signaling for partially precoded csi-rs and csi feedback

Patent metadata

Field	Value
Publication number	US-2016156401-A1
Application number	US-201514954838-A
Country	US
Kind code	A1
Filing date	Nov 30, 2015
Priority date	Dec 2, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

User equipment (UE) is configured to receive two types of channel state information (CSI) reference signals (CSI-RS), the first containing more antenna ports and measured less often than the second. A first CSI report is based on first type CSI-RS and a second CSI report on the second type CSI-RS. The second type CSI-RS is at least partially precoded in response to the first CSI report, is precoded for the specific UE, and is transmitted more often than the first type CSI-RS, while the first type CSI-RS is not precoded. The first CSI report contains a first precoding matrix indicator (PMI) parameter and the second CSI report contains only a second PMI parameter of a two-PMI codebook, where the first PMI parameter is a long-term and wideband PMI. The first PMI is derived from measuring the first type CSI-RS in a plurality of subframes and resource blocks.

First claim

What is claimed is:

1 . A base station, comprising:
a transmitter configured to transmit a signal configuring a user equipment with receiving two channel state information (CSI) reference signal (CSI-RS) resources, wherein a first of the CSI-RS resources contains more ports and is measured less often than a second of the CSI-RS resources; a receiver configured to receive two types of CSI reports from the user equipment, a first of the CSI reports associated with the first CSI-RS resource and a second of the CSI reports associated with the second CSI-RS resource; and a controller configured to precode the second CSI-RS resource in response to the first CSI report, wherein the transmitter is configured to transmit the first CSI-RS resource in a first set of subframes and the second CSI-RS resource in a second set of subframes.

2 . The base station according to claim 1 , wherein the first CSI-RS resource is not precoded.

3 . The base station according to claim 1 , wherein the second CSI-RS resource is precoded specifically for the user equipment.

4 . The base station according to claim 1 , wherein the first CSI report contains a first precoding matrix indicator (PMI) parameter of a two-PMI codebook, and the second CSI report contains a PMI parameter of a one-PMI codebook.

5 . The base station according to claim 4 , wherein the first PMI parameter is calculated from a plurality of subframes and resource blocks carrying the first CSI-RS resource.

6 . The base station according to claim 4 , wherein the first PMI parameter is a long-term and wideband PMI.

7 . A user equipment, comprising:
a processor configured to
measure channel state information reference signals (CSI-RS) of at least a first resource and a second resource, wherein the first CSI-RS resource corresponds to more ports than the second CSI-RS resource and wherein the first CSI-RS resource is measured less often than the second CSI-RS resource, and
calculate two types of CSI reports, wherein a first of the two types of CSI reports is generated in response to the first CSI-RS resource and a second of the two types of CSI reports is generated in response to the second CSI-RS resource; and
a transmitter configured to report the two types of CSI reports.

8 . The user equipment according to claim 7 , wherein the first CSI-RS resource is not precoded.

9 . The user equipment according to claim 7 , wherein the second CSI-RS resource is precoded specifically for the user equipment.

10 . The user equipment according to claim 7 , wherein the first CSI report contains at least a first precoding matrix indicator (PMI) parameter of a two-PMI codebook and the second CSI report contains a PMI parameter of a one-PMI codebook.

11 . The user equipment in claim 10 , wherein the first PMI parameter is calculated from a plurality of subframes and resource blocks carrying the first CSI-RS resource.

12 . The user equipment in claim 10 , wherein the first PMI parameter is a long-term and wideband PMI.

13 . A method of operating a base station, comprising:
transmitting a signal configuring a user equipment with receiving two channel state information (CSI) reference signal (CSI-RS) resources, wherein a first of the CSI-RS resources contains more ports and is measured less often than a second of the CSI-RS resources; receiving two types of CSI reports from the user equipment, a first of the CSI reports associated with the first CSI-RS resource and a second of the CSI reports associated with the second CSI-RS resource; precoding the second CSI-RS resource in response to the first CSI report; transmitting the first CSI-RS resource in a first set of subframes and the second CSI-RS resource in a second set of subframes.

14 . The method according to claim 13 , wherein the first CSI-RS type is not precoded and the second CSI-RS resource is precoded specifically for the user equipment.

15 . The method according to claim 13 , wherein the first CSI report contains a first precoding matrix indicator (PMI) parameter of a two-PMI codebook, and the second CSI report contains a PMI parameter of a one-PMI codebook.

16 . The method according to claim 15 , wherein the first PMI parameter is a long-term and wideband PMI calculated from a plurality of subframes and resource blocks carrying the first CSI-RS resource.

17 . A method of operating a user equipment, comprising:
measuring channel state information reference signals (CSI-RS) of at least a first resource and a second resource, wherein the first CSI-RS resource corresponds to more ports than the second CSI-RS resource and wherein the first CSI-RS resource is measured less often than the second CSI-RS resource; calculating two types of CSI reports, wherein a first of the two types of CSI reports is generated in response to the first CSI-RS resource and a second of the two types of CSI reports is generated in response to the second CSI-RS resource; and reporting the two types of CSI reports.

18 . The method according to claim 17 , wherein the first CSI-RS resource is not precoded and the second CSI-RS resource is precoded specifically for the user equipment.

19 . The method according to claim 17 , wherein the first CSI report contains a first precoding matrix indicator (PMI) parameter of a two-PMI codebook, and the second CSI report contains a PMI parameter of a one-PMI codebook.

20 . The method according to claim 19 , wherein the first PMI parameter is is a long-term and wideband PMI calculated from a plurality of subframes and resource blocks carrying the first CSI-RS resource.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Onggosanusi Eko
• Ng Boon Loong
• Nam Young-Han
• Gha Hee Don

Classifications

• H04B7/0645 Primary

  Variable feedback · CPC title

• H04B7/0482

  Adaptive codebooks · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title

• H04L5/005

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

• H04B7/0456

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title