Precoding matrix indicator feedback method, receive end, and transmit end

Patent metadata

Field	Value
Publication number	US-9350435-B2
Application number	US-201514924395-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Apr 28, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

The present invention provides a precoding matrix indicator feedback method, a receive end, and a transmit end. The method includes: selecting, by a receive end based on a reference signal, a precoding matrix W from a codebook, where a coefficient α is used to perform phase adjustment on φ n in W, φ n represents a phase difference between weighted values of a first antenna group and a second antenna group of a transmit end for a transmission signal from a same transmission layer,
φ n ∈ { ⅇ j ⁢ ⁢ 2 ⁢ π ⁢ ⁢ n Q } ,
and the first antenna group and the second antenna group belong to a same multi-antenna system; and sending, by the receive end, a precoding matrix indicator (PMI) to the transmit end. In this way, using the coefficient α to perform the phase adjustment on φ n can increase a size of a codebook set applicable to different antenna configurations, and improve precision of the receive end to feed back a PMI.

First claim

What is claimed is:

1. A precoding matrix indicator feedback method, comprising:
selecting, by a receive end, based on a reference signal, a precoding matrix W from a codebook, wherein a coefficient α is used to perform phase adjustment on φ n in the W, the φ n represents a phase difference between weighted values of a first antenna group and a second antenna group of a transmit end for a transmission signal from a same transmission layer, the

φ
n

∈

{

ⅇ

j
⁢

⁢
2
⁢
π
⁢

⁢
n

Q

}

,

the n is a non-negative integer, the Q is a positive integer, and the first antenna group and the second antenna group belong to a same multi-antenna system; and
sending, by the receive end, a precoding matrix indicator (PMI) of the precoding matrix W to the transmit end.

2. The method according to claim 1 , wherein the method further comprises:
determining, by the receive end, a rank indicator based on the reference signal, wherein the rank indicator corresponds to the number of useful transmission layers; and
the selecting, by a receive end, based on a reference signal, a precoding matrix W from a codebook comprises:
selecting, by the receive end, based on the reference signal, the W corresponding to the rank indicator from the codebook.

3. The method according to claim 2 , wherein
when the rank indicator is 1, the precoding matrix is:

W
=

W
1

·

W
2

=

[

X
L

0

0

X
L

]

·

[

Y
1

αφ
n

⁢

Y
2

]

=

[

X
L

0

0

X
L

]

·

[

e

m
⁢

⁢
1

α
⁢

⁢

φ
n

⁢

e

m
⁢

⁢
2

]

;

wherein the

X
L

=

[

1

1

ⅇ

j

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhang Leiming
• Wu Qiang
• Liu Jianghua

Classifications

• H04B7/0417 Primary

  Feedback systems · CPC title

• H04L1/06 Primary

  using space diversity · CPC title

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H04B7/0456 Primary

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

• H04B7/0639 Primary

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title