US 8,477,867 B2Granted

Method and apparatus for cooperative MIMO transmission operation in multicell wireless network

AssigneesLG Electronics Inc., Industry-Academic Cooperation Foundation, Yonsei University

InventorsSuck Chel Yang, Dong Ku Kim, Yo Han Kim, Jang Hoon Yang, Hyung Tae Kim, Hyuk Jin Chae

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method and apparatus of configuring a multi-cell precoding matrix for a multiple input multiple output (MIMO) operation in a wireless communication system in which a plurality of base stations participate in cooperative communication is provided. A multi-cell precoding matrix is configured using one or more single-cell precoding matrices, and wherein coefficients to be multiplied by the single-cell precoding matrices satisfy a condition in which the product between the multi-cell precoding matrix and a Hermitian matrix of the multi-cell precoding matrix is a unitary matrix. According to the embodiment of the present invention, it is not necessary for all base stations to perfectly know channel information. In addition, a feedback overhead is not high, and complexity is low.

Claims7

Dependent claims

A method of configuring a multi-cell precoding matrix for a multiple input multiple output (MIMO) operation in a wireless communication system in which a plurality of base stations participate in cooperative communication, the method comprising:

configuring the multi-cell precoding matrix using one or more single-cell precoding matrices,
wherein coefficients to be multiplied by the single-cell precoding matrices satisfy a condition in which the product between the multi-cell precoding matrix and a Hermitian matrix of the multi-cell precoding matrix is a unitary matrix,
wherein the multi-cell precoding matrix is configured by assigning a same single-cell precoding matrix in a row direction or a column direction of the multi-cell precoding matrix, and
wherein the multi-cell precoding matrix is obtained according to Equation (E-1) and Equation (E-2):
W
co
C
=
1
C
⁡
[
a
11
⁢
W
p
a
12
⁢
W
p
⋯
a
1
⁢
C
⁢
W
p
a
21
⁢
W
q
a
22
⁢
W
q
⋯
a
2
⁢
C
⁢
W
q
⋮
⋮
⋮
⋮
a
C
⁢
⁢
1
⁢
W
r
a
C
⁢
⁢
2
⁢
W
r
⋯
a
CC
⁢
W
r
]
⁢
⁢
or
⁢
⁢
W
co
C
=
1
C
⁡
[
a
11
⁢
W
p
a
12
⁢
W
q
⋯
a
1
⁢
C
⁢
W
r
a
21
⁢
W
p
a
22
⁢
W
q
⋯
a
2
⁢
C
⁢
W
r
⋮
⋮
⋮
⋮
a
C
⁢
⁢
1
⁢
W
p
a
C
⁢
⁢
2
⁢
W
q
⋯
a
CC
⁢
W
r
]
,
⁢
and
(
E
⁢
-
⁢
1
)
a
mn
=
exp
⁡
(
j
⁢
2
⁢
π
⁡
(
m
-
1
)
⁢
(
n
-
1
)
C
)
,
(
E
⁢
-
⁢
2
)
where Wp, Wq, . . . , Wr each denotes a single-cell precoding matrix, and amn is any value satisfying WcoH·Wco=IC×L, wherein WcoH is a Hermitian matrix of Wco, m=1, 2, . . . , C, and where C is the number of base stations, n=1, 2, . . . , C, and IC×L is a C×L unitary matrix).

192 more elements

A feedback method for a multiple input multiple output (MIMO) operation in a wireless communication system in which a plurality of base stations participate in cooperative communication, the method comprising:

measuring signal to interference plus noise ratios (SINRs) for all transmit data;
selecting one of multi-cell precoding matrices having an optimal SINR from the measured SINRs;
and
transmitting indication information for the selected multi-cell precoding matrix and an SINR measured for the selected multi-cell precoding matrix,
wherein in the transmitting of the indication information and the SINR, a total of min (NR, 2L) higher SINRs (where NR denotes the number of antennas of a receiver, L denotes the number of pieces of transmit data sent from one base station, and min(a,b) denotes a smaller or equal value between a and b) for one of the multi-cell precoding matrices capable of maximizing a data rate among all of the multi-cell precoding matrices and precoding vector indices corresponding to the SINRs are transmitted.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/997,209Filed 3 Sep 2009
Priority: KR 10-2008-009476726 Sep 2008
Published: US 2011/0090945 A121 Apr 2011
Granted: 2 Jul 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04B 7/0617
Of weighted versions of same signal: for beam forming
H04B 7/024
Site diversity; Macro-diversity: co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input…
H04B 7/0632
Feedback content: channel quality parameters, e.g. channel quality indicator [CQI]
H04B
Transmission