Multiple input multiple output communication system using codebook corresponding to each reporting mode
A multiple input multiple output (MIMO) communication system using a first codebook and a second codebook is provided. The first codebook and the second codebook may independently exist, or may exist in a form of an overall codebook in which the first codebook and the second codebook are integrated with each other. A receiver may extract a first precoding matrix indicator from the first codebook, and may extract a second precoding matrix indicator from the second codebook. The receiver may also extract the first precoding matrix indicator and the second precoding matrix indicator from the overall codebook. The first precoding matrix indicator and the second precoding matrix indicator may be fed back to a transmitter. The transmitter may determine a precoding matrix based on the first precoding matrix indicator and the second precoding matrix indicator.
1. A communication method of a receiver in a wireless communication system, the communication method comprising:
obtaining a rank indicator;
obtaining a first precoding matrix indicator based on the rank indicator;
obtaining a second precoding matrix indicator associated with the first precoding matrix indicator;
when the rank indicator is 1,
transmitting the rank indicator,
transmitting the first precoding matrix indicator obtained based on a subset {0, 2, 4, 6, 8, 10, 12, 14} of a first codebook, the second precoding matrix indicator and a wideband channel quality index (CQI); and
when the rank indicator is 2,
transmitting the rank indicator, and
transmitting the first precoding matrix indicator obtained based on a subset {0, 2, 4, 6, 8, 10, 12, 14} of the first codebook, the second precoding matrix indicator and a wideband channel quality index(CQI),
wherein when the rank indicator is 1 or 2, the first precoding matrix indicator is 3 bits, and the second precoding matrix indicator is 1 bit.
2. The communication method of claim 1 , wherein a combination of the first precoding matrix indicator and the second precoding matrix indicator indicates a single recommended precoding matrix.
3. The communication method of claim 1 , wherein a combination of the first precoding matrix indicator and the second precoding matrix indicator indicates one of recommended precoding matrix candidates disclosed in the following Table 1:
TABLE 1
W (1) 0,0
W (1) 0,2
W (1) 4,0
W (1) 4,2
W (1) 8,0
W (1) 8,2
W (1) 12,0
W (1) 12,2
W (1) 16,0
W (1) 16,2
W (1) 20,0
W (1) 20,2
W (1) 24,0
W (1) 24,2
W (1) 28,0
W (1) 28,2
wherein
W
m
,
n
(
1
)
=
1
8
[
v
m
φ
n
v
m
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.
4. The communication method of claim 1 , wherein a combination of the first precoding matrix indicator and the second precoding matrix indicator indicates one of recommended precoding matrix candidates disclosed in the following Table 2:
TABLE 2
W (2) 0,0,0
W (2) 0,0,1
W (2) 4,4,0
W (2) 4,4,1
W (2) 8,8,0
W (2) 8,8,1
W (2) 12,12,0
W (2) 12,12,1
W (2) 16,16,0
W (2) 16,16,1
W (2) 20,20,0
W (2) 20,20,1
W (2) 24,24,0
W (2) 24,24,1
W (2) 28,28,0
W (2) 28,28,1
wherein
W
m
,
m
′
,
n
(
2
)
=
1
4
[
v
m
v
m
′
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.
5. The communication method of claim 1 , wherein a physical uplink control channel (PUCCH) mode is corresponding to 1-1.
6. The communication method of claim 1 , further comprising:
when the rank indicator is 3,
transmitting the rank indicator, and
transmitting the first precoding matrix indicator obtained based on a subset {0, 2} of the first codebook, the second precoding matrix indicator and a wideband channel quality index(CQI),
wherein when the rank indicator is 3, the first precoding matrix indicator is 1 bit, and the second precoding matrix indicator is 3 bits.
7. The communication method of claim 1 , further comprising:
when the rank indicator is 5 or 6,
transmitting the rank indicator, and
transmitting the first precoding matrix indicator obtained based on a subset {0, 1, 2, 3} of the first codebook, the second precoding matrix indicator and a wideband channel quality index(CQI),
wherein when the rank indicator is 5 or 6, the first precoding matrix indicator is 2 bits, and the second precoding matrix indicator is 0 bit.
8. A communication method of a receiver in a multiple input multiple output (MIMO) communication system, the communication method comprising:
feeding back, to a transmitter, a first precoding matrix indicator corresponding to a first codeword index included in a first codebook in order to indicate a recommended precoding matrix at a first reporting point; and
feeding back, to the transmitter, a second precoding matrix indicator corresponding to a second codeword index included in a second codebook in order to indicate a recommended precoding matrix at a second reporting point,
wherein the second precoding matrix indicator indicates, as the recommended precoding matrix at the second reporting point, one of candidates disclosed in the following Table 3:
TABLE 3
W (2) 0,0,0
W (2) 2,2,0
W (2) 2,2,0
W (2) 4,4,0
W (2) 4,4,0
W (2) 6,6,0
W (2) 6,6,0
W (2) 8,8,0
W (2) 8,8,0
W (2) 10,10,0
W (2) 10,10,0
W (2) 12,12,0
W (2) 12,12,0
W (2) 14,14,0
W (2) 14,14,0
W (2) 16,16,0
W (2) 16,16,0
W (2) 18,18,0
W (2) 18,18,0
W (2) 20,20,0
W (2) 20,20,0
W (2) 22,22,0
W (2) 22,22,0
W (2) 24,24,0
W (2) 24,24,0
W (2) 26,26,0
W (2) 26,26,0
W (2) 28,28,0
W (2) 28,28,0
W (2) 30,30,0
W (2) 30,30,0
W (2) 0,0,0
W (2) 1,1,0
W (2) 3,3,0
W (2) 3,3,0
W (2) 5,5,0
W (2) 5,5,0
W (2) 7,7,0
W (2) 7,7,0
W (2) 9,9,0
W (2) 9,9,0
W (2) 11,11,0
W (2) 11,11,0
W (2) 13,13,0
W (2) 13,13,0
W (2) 15,15,0
W (2) 15,15,0
W (2) 17,17,0
W (2) 17,17,0
W (2) 19,19,0
W (2) 19,19,0
W (2) 21,21,0
W (2) 21,21,0
W (2) 23,23,0
W (2) 23,23,0
W (2) 25,25,0
W (2) 25,25,0
W (2) 27,27,0
W (2) 27,27,0
W (2) 29,29,0
W (2) 29,29,0
W (2) 31,31,0
W (2) 31,31,0
W (2) 1,1,0
wherein
W
m
,
m
′
,
n
(
2
)
=
1
4
[
v
m
v
m
′
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.
9. A communication method of a receiver in a multiple input multiple output (MIMO) communication system, the communication method comprising:
feeding back, to a transmitter, a first precoding matrix indicator corresponding to a first codeword index included in a first codebook in order to indicate a recommended precoding matrix at a first reporting point; and
feeding back, to the transmitter, a second precoding matrix indicator corresponding to a second codeword index included in a second codebook in order to indicate a recommended precoding matrix at a second reporting point,
wherein the second precoding matrix indicator indicates, as the recommended precoding matrix at the second reporting point, one of candidates disclosed in the following Table 4:
TABLE 4
W (4) 0,8,0
W (4) 8,16,0
W (4) 16,24,0
W (4) 24,32,0
W (4) 2,10,0
W (4) 10,18,0
W (4) 18,26,0
W (4) 26,34,0
W (4) 4,12,0
W (4) 12,20,0
W (4) 20,28,0
W (4) 28,36,0
W (4) 6,14,0
W (4) 14,22,0
W (4) 22,30,0
W (4) 30,38,0
wherein
W
m
,
m
′
,
n
(
4
)
=
1
32
[
v
m
v
m
′
v
m
v
m
′
φ
n
v
m
φ
n
v
m
′
-
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.
10. A communication method of a transmitter in a multiple input multiple output (MIMO) communication system, the communication method comprising:
receiving, from a receiver, a first precoding matrix indicator corresponding to a first codeword index included in a first codebook and a second precoding matrix indicator corresponding to a second codeword index included in a second codebook; and
obtaining a precoding matrix based on the first precoding matrix indicator and the second precoding matrix indicator,
wherein a combination of the first precoding matrix indicator and the second precoding matrix indicator indicates one of recommended precoding matrix candidates disclosed in one of the following Table 5 and Table 6:
TABLE 5
W (1) 0,0
W (1) 0,2
W (1) 4,0
W (1) 4,2
W (1) 8,0
W (1) 8,2
W (1) 12,0
W (1) 12,2
W (1) 16,0
W (1) 16,2
W (1) 20,0
W (1) 20,2
W (1) 24,0
W (1) 24,2
W (1) 28,0
W (1) 28,2
wherein
W
m
,
n
(
1
)
=
1
8
[
v
m
φ
n
v
m
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T
TABLE 6
W (2) 0,0,0
W (2) 0,0,1
W (2) 4,4,0
W (2) 4,4,1
W (2) 8,8,0
W (2) 8,8,1
W (2) 12,12,0
W (2) 12,12,1
W (2) 16,16,0
W (2) 16,16,1
W (2) 20,20,0
W (2) 20,20,1
W (2) 24,24,0
W (2) 24,24,1
W (2) 28,28,0
W (2) 28,28,1
wherein
W
m
,
m
′
,
n
(
2
)
=
1
4
[
v
m
v
m
′
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.
11. A communication method of a transmitter in a multiple input multiple output (MIMO) communication system, the communication method comprising:
receiving, from a receiver, a first precoding matrix indicator corresponding to a first codeword index included in a first codebook, the first precoding matrix indicator indicating a recommended precoding matrix at a first reporting point;
receiving, from the receiver, a second precoding matrix indicator corresponding to a second codeword index included in a second codebook, the second precoding matrix indicator indicating a recommended precoding matrix at a second reporting point; and
obtaining the recommended precoding matrix at the second reporting point based on the second precoding matrix indicator received at the second reporting point,
wherein the second precoding matrix indicator indicates, as the recommended precoding matrix at the second reporting point, one of recommended precoding matrix candidates disclosed in one of the following Table 3 and Table 4:
TABLE 3
W (2) 0,0,0
W (2) 2,2,0
W (2) 2,2,0
W (2) 4,4,0
W (2) 4,4,0
W (2) 6,6,0
W (2) 6,6,0
W (2) 8,8,0
W (2) 8,8,0
W (2) 10,10,0
W (2) 10,10,0
W (2) 12,12,0
W (2) 12,12,0
W (2) 14,14,0
W (2) 14,14,0
W (2) 16,16,0
W (2) 16,16,0
W (2) 18,18,0
W (2) 18,18,0
W (2) 20,20,0
W (2) 20,20,0
W (2) 22,22,0
W (2) 22,22,0
W (2) 24,24,0
W (2) 24,24,0
W (2) 26,26,0
W (2) 26,26,0
W (2) 28,28,0
W (2) 28,28,0
W (2) 30,30,0
W (2) 30,30,0
W (2) 0,0,0
W (2) 1,1,0
W (2) 3,3,0
W (2) 3,3,0
W (2) 5,5,0
W (2) 5,5,0
W (2) 7,7,0
W (2) 7,7,0
W (2) 9,9,0
W (2) 9,9,0
W (2) 11,11,0
W (2) 11,11,0
W (2) 13,13,0
W (2) 13,13,0
W (2) 15,15,0
W (2) 15,15,0
W (2) 17,17,0
W (2) 17,17,0
W (2) 19,19,0
W (2) 19,19,0
W (2) 21,21,0
W (2) 21,21,0
W (2) 23,23,0
W (2) 23,23,0
W (2) 25,25,0
W (2) 25,25,0
W (2) 27,27,0
W (2) 27,27,0
W (2) 29,29,0
W (2) 29,29,0
W (2) 31,31,0
W (2) 31,31,0
W (2) 1,1,0
wherein
W
m
,
m
′
,
n
(
2
)
=
1
4
[
v
m
v
m
′
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T
TABLE 4
W (4) 0,8,0
W (4) 8,16,0
W (4) 16,24,0
W (4) 24,32,0
W (4) 2,10,0
W (4) 10,18,0
W (4) 18,26,0
W (4) 26,34,0
W (4) 4,12,0
W (4) 12,20,0
W (4) 20,28,0
W (4) 28,36,0
W (4) 6,14,0
W (4) 14,22,0
W (4) 22,30,0
W (4) 30,38,0
wherein
W
m
,
m
′
,
n
(
4
)
=
1
32
[
v
m
v
m
′
v
m
v
m
′
φ
n
v
m
φ
n
v
m
′
-
φ
n
v
m
-
φ
n
v
m
′
]
,
φ
n
=
e
j
π
n
/
2
,
and ν m =[1 e j2πn/32 e j4πn/32 e j6πn/32 ] T , and
wherein W denotes a precoding matrix, v denotes a column vector, and m and n are variables.