Method and device for beam training using beamforming codebook

Patent metadata

Field	Value
Publication number	US-11916626-B2
Application number	US-202117515218-A
Country	US
Kind code	B2
Filing date	Oct 29, 2021
Priority date	Jul 20, 2021
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

The disclosure relates to a 5G or pre-5G communication system for supporting higher data transmission rates than 4G communication systems such as LTE systems. According to an embodiment, a method performed by a base station supporting beam training using a beamforming codebook may comprise storing a plurality of codebooks corresponding to a plurality of different beamwidths, receiving a beam adjustment request from a user equipment (UE), determining, among the plurality of codebook, a codebook including beam codebooks for beam coverages including a beamwidth corresponding to a channel state of the UE, in response to receiving the beam adjustment request, and transmitting, to the UE, signals that are beamformed based on the codebook through a plurality of transmission beams using digital beamforming matrixes of the codebook.

First claim

What is claimed is:

1. A method performed by a base station supporting beam training using a beamforming codebook, the method comprising:
storing a plurality of codebooks corresponding to a plurality of different beamwidths;
receiving a beam adjustment request from a user equipment (UE);
determining, among the plurality of codebooks, a codebook including beam codebooks for beam coverages including a beamwidth corresponding to a channel state of the UE, in response to receiving the beam adjustment request; and
transmitting, to the UE, signals that are beamformed based on the codebook through a plurality of transmission beams using digital beamforming matrixes of the codebook,
wherein each beam codebook q m of the beam codebooks included in the codebook is configured based on a product of a transmission analog beamforming matrix and a baseband digital processing vector that are obtained based on a beam codeword v m for an m-th beam coverage, and
wherein the beam codeword v m is obtained based on a beam gain vector [g m ] k corresponding to a k-th over-sampled angle of departure (AoD) and an array steering matrix A.

2. The method of claim 1 , wherein the beam codeword v m is obtained by an equation below:

v
m

=

(

AA
H

)

-
1

⁢
A
⁢

g
~

m



(

AA
H

)

-
1

⁢
A
⁢

g
~

m



2

wherein the beam gain vector [g m ] k is estimated based on an amplitude factor T(m) and a phase factor a k for mitigating beam gain fluctuation within the m-th beam coverage, by an equation below:

[

g
^

m

]

k

=

1

T
⁡
(

a
k

)

⁢

exp
[

-
j

⁢

(

N
-
1

)

⁢
π
⁢

a
k

2

]

,

k
∈

{

1
,
2
,
…

,
K

}

wherein N is a number of antennas of the base station, and K is a number of over-sampled AoDs.

3. The method for claim 1 , wherein the beam adjustment request includes at least one of information indicating the channel state of the UE or information indicating a desired beam quality of the UE.

4. The method of claim 1 , further comprising:
receiving, from the UE, a report indicating one or more transmission beams;
transmitting, based on the report, a signal requesting to enable the beam training through at least one transmission beam among the plurality of transmission beams; and
receiving, from the UE, a signal requesting to terminate the beam training.

5. A method performed by a user equipment (UE) performing beam training using a beamforming codebook, the method comprising:
storing a plurality of codebooks corresponding to a plurality of different beamwidths;
transmitting a beam adjustment request to a base station;
determining, among the plurality of codebooks, a codebook including beam codebooks for beam coverages including a beamwidth corresponding to a channel state of the UE based on the beam adjustment request; and
performing beam training based on receiving signals that are beamformed through a plurality of transmission beams from the base station using digital beamforming matrixes of the codebook,
wherein each beam codebook q m of the beam codebooks included in the codebook is configured based on a product of a transmission analog beamforming matrix and a baseband digital processing vector that are obtained based on a beam codeword v m for an m-th beam coverage, and
wherein the beam codeword v m is obtained based on a beam gain vector [g m ] k corresponding to a k-th over-sampled angle of departure (AoD) and an array steering matrix A.

6. The method of claim 5 , wherein the beam codeword v m is obtained, by an equation below:

v
m

=

(

AA
H

)

-
1

⁢
A
⁢

g
~

m

Assignees

• Samsung Electronics Co Ltd
• Univ Yonsei Iacf

Inventors

• Lee Seunghyun
• Eom Chahyeon
• Lee Kwonjong
• Lee Chungyong
• Yu Jieun
• Lee Hyungje

Classifications

• H04B7/0408

  using two or more beams, i.e. beam diversity · CPC title

• H04B7/0682

  using phase diversity (e.g. phase sweeping) · CPC title

• H04B7/06952

  Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping · CPC title

• H04B7/0478 Primary

  Special codebook structures directed to feedback optimisation · CPC title

• H04B7/0456 Primary

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