Reporting of coefficients for channel state information

Patent metadata

Field	Value
Publication number	US-12348288-B2
Application number	US-202318392656-A
Country	US
Kind code	B2
Filing date	Dec 21, 2023
Priority date	Dec 12, 2018
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

A method performed by a wireless device ( 510, 800, 1200 ) for reporting channel state information (CSI) for a downlink channel is disclosed. The method comprises transmitting ( 601, 705 ) a CSI report for the downlink channel to a network node ( 560, 1100 ), the CSI report comprising: a set of reported coefficients; an indication of how the network node is to interpret the set of reported coefficients; and an indication of a payload size of the set of the reported coefficients.

First claim

The invention claimed is:

1. A method performed by a wireless device for reporting channel state information (CSI) for a downlink channel, the method comprising:
transmitting a CSI report for the downlink channel to a network node, the CSI report comprising:
a quantized representation of a set of reported coefficients;
an indication of how the network node is to interpret the set of reported coefficients, wherein the indication of how the network node is to interpret the set of reported coefficients indicates the set of reported coefficients as a subset of a set of candidate reported coefficients; and
an indication of a payload size of the set of the reported coefficients,

wherein:
in a quantization range for the set of reported coefficients, the amplitude quantization values are

1

1
⁢
2
⁢
8

,

1
/
6

⁢
4

,

1
/
3

⁢
2

,

1
/
1

⁢
6

,

1
/
8

,

1
/
4

,

1
/
2

⁢

and
⁢

1

;

 and
these amplitude quantization values are associated with the quantization indices 0, 1, 2, 3, 4, 5, 6 and 7, respectively.

2. The method of claim 1 , further comprising:
estimating the downlink channel;
determining, based on the estimated downlink channel, a plurality of coefficients;
determining that a subset of the plurality of coefficients are quantized to zero; and
omitting the determined subset of coefficients from the CSI report.

3. The method of claim 1 , wherein the CSI report indicates a plurality of precoder vectors, wherein the precoder vectors are linear combinations of spatial-domain vectors, wherein the coefficients for the spatial-domain vectors in the linear combinations of spatial-domain vectors are parameterized in the frequency-domain as linear combinations of a set of frequency-domain vectors and a set of coefficients for the frequency-domain vectors in the linear combinations of the set of frequency-domain vectors, wherein the reported coefficients are the coefficients for the frequency-domain vectors in the linear combinations of the set of frequency-domain vectors, and wherein the frequency-domain vectors are reported in the CSI report.

4. The method of claim 1 , further comprising:
receiving a CSI report configuration, the CSI report configuration indicating a maximum number of non-zero coefficients that the wireless device can include in the CSI report.

5. The method of claim 2 , wherein the plurality of coefficients comprises one or more of amplitude coefficients and phase coefficients.

6. A method performed by a network node for receiving channel state information (CSI) for a downlink channel, the method comprising:
receiving a CSI report for the downlink channel from a wireless device, the CSI report comprising:
a quantized representation of a set of reported coefficients;
an indication of how the network node is to interpret the set of reported coefficients, wherein the indication of how the network node is to interpret the set of reported coefficients indicates the set of reported coefficients as a subset of a set of candidate reported coefficients; and
an indication of a payload size of the set of the reported coefficients,

wherein:
in a quantization range for the set of reported coefficients, the amplitude quantization values are

1

1
⁢
2
⁢
8

,

1
/
6

⁢
4

,

1
/
3

⁢
2

,

1
/
1

⁢
6

,

1
/
8

,

1
/
4

,

1
/
2

⁢

and
⁢

1

;

 and
these amplitude quantization values are associated with the quantization indices 0, 1, 2, 3, 4, 5, 6 and 7, respectively.

7. The method of claim 6 , wherein the CSI report indicates a plurality of precoder vectors, wherein the precoder vectors are linear combinations of spatial-domain vectors, wherein the coefficients for the spatial-domain vectors in the linear combinations of spatial-domain vectors are parameterized in the frequency-domain as linear combinations of a set of frequency-domain vectors and a set of coefficients for the frequency-domain vectors in the linear combinations of the set of frequency-domain vectors, wherein the reported coefficients are the coefficients for the frequency-domain vectors in the linear combinations of the set of frequency-domain vectors, and wherein the frequency-domain vectors are reported in the CSI report.

8. The method of claim 6 , further comprising:
transmitting a CSI report configuration to the wireless device, the CSI report configuration indicating a maximum number of non-zero coefficients that the wireless device can include in th

Assignees

• Ericsson Telefon Ab L M

Inventors

• Faxér Sebastian
• Timo Roy
• Wernersson Niklas
• Girnyk Maksym
• Wang Zhao

Classifications

• H04B7/0478

  Special codebook structures directed to feedback optimisation · CPC title

• H04B7/0481

  using subset selection of codebooks · CPC title

• H04B7/063

  Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection · CPC title

• H04B7/0626 Primary

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

• H04B7/0645 Primary

  Variable feedback · CPC title