Data transmitting and receiving method using phase shift based precoding and transceiver supporting the same
A method for performing a precoding based on a generalized phase shift or a precoding based on an extended phase shift in a Multi-Input Multi-Output (MIMO) system employing several sub-carriers, and a transceiver for supporting the same are disclosed. A phase-shift-based precoding matrix is generalized by multiplying a diagonal matrix for a phase shift by a unitary matrix for maintaining orthogonality between sub-carriers. In this case, a diagonal matrix part may be extended by multiplying a precoding matrix for removing interference between sub-carriers by a diagonal matrix for a phase shift. By generalization and extension of the phase-shift-based precoding, a transceiver is more simplified, and communication efficiency increases.
1. A method for transmitting data to a reception end device in a Multi-Input Multi-Output (MIMO) system from a transmission end device, the method comprising:
precoding data by multiplying a phase-shift-based precoding matrix to a data matrix representing the data; and
transmitting the precoded data to the reception end device using multiple antennas,
wherein the phase-shift-based precoding matrix has a form of multiplication of a precoding matrix (P), a diagonal matrix (D) and an unitary matrix (U),
wherein the precoding matrix is cyclically selected from a codebook having (N c ) precoding matrixes using a modulo operation,
wherein the modulo operation is defined by using a resource index (k) and the (N c ).
2. The method of claim 1 , wherein the phase-shift-based precoding matrix is represented by a following equation:
(
ℙ
N
t
×
R
)
(
ⅇ
jθ
1
k
0
…
0
0
ⅇ
jθ
2
k
…
0
⋮
⋮
⋱
⋮
0
0
…
ⅇ
jθ
R
k
)
(
𝕌
R
×
R
)
[
Equation
]
where ( N t ×R )is the precoding matrix for the resource index (k), N t is a number of the multiple antennas, ( R×R )is the unitary matrix, θ i , is a phase angle value, and (R) corresponds to a spatial multiplexing rate.
3. The method of claim 1 , wherein the resource index (k) is one of a subcarrier index and a virtual subcarrier index.
4. A transceiver for transmitting data to a reception end device in a Multi-Input Multi-Output (MIMO) system, the transceiver comprising:
a precoding module for precoding data by multiplying a phase-shift-based precoding matrix to a data matrix representing the data; and
multiple antennas for transmitting the precoded data to the reception end device,
wherein the phase-shift-based precoding matrix has a form of multiplication of a precoding matrix (P), a diagonal matrix (D) and an unitary matrix (U),
wherein the precoding matrix is cyclically selected from a codebook having (N c ) precoding matrixes using a modulo operation,
wherein the modulo operation is defined by using a resource index (k) and the (N c ).
5. The transceiver of claim 4 , wherein the phase-shift-based precoding matrix is represented by a following equation:
(
ℙ
N
t
×
R
)
(
ⅇ
jθ
1
k
0
…
0
0
ⅇ
jθ
2
k
…
0
⋮
⋮
⋱
⋮
0
0
…
ⅇ
jθ
R
k
)
(
𝕌
R
×
R
)
[
Equation
]
where ( N t ×R )is the precoding matrix for the resource index (k), N t is a number of the multiple antennas, ( R×R )is the unitary matrix, θ i is a phase angle value, and (R) corresponds to a spatial multiplexing rate.
6. The transceiver of claim 4 , wherein the resource index (k) is one of a subcarrier index and a virtual subcarrier index.
7. A method for receiving data at a reception end device in a Multi-Input Multi-Output (MIMO) system from a transmission end device, the method comprising:
receiving precoded data from the transmission end device having multiple antennas; and
performing opposite function for precoding data at the transmission end device using a phase-shifted-based precoding matrix for each of resource indexes (k),
wherein the phase-shift-based precoding matrix has a form of multiplication of a precoding matrix (P), a diagonal matrix (D) and an unitary matrix (U),
wherein the precoding matrix is cyclically selected from a codebook having (Nc) precoding matrixes using a modulo operation,
wherein the modulo operation is defined by using the resource index (k) and the (Nc).
8. The method of claim 7 , wherein the phase-shift-based precoding matrix is represented by a following equation:
(
ℙ
N
t
×
R
)
(
ⅇ
jθ
1
k
0
…
0
0
ⅇ
jθ
2
k
…
0
⋮
⋮
⋱
⋮
0
0
…
ⅇ
jθ
R
k
)
(
𝕌
R
×
R
)
[
Equation
]
where ( N t ×R ) is the precoding matrix for the resource index (k), N t is a number of the multiple antennas, ( R×R ) is the unitary matrix, θ i is a phase angle value, and (R) corresponds to a spatial multiplexing rate.
9. The method of claim 7 , wherein the resource index (k) is one of a subcarrier index and a virtual subcarrier index.
10. A transceiver for receiving data from a transmission end device in a Multi-Input Multi-Output (MIMO) system, the transceiver comprising:
one or more antennas for receiving precoded data from the transmission end device having multiple antennas; and
a MIMO decoder for performing opposite function for precoding data at the transmission end device using a phase-shifted-based precoding matrix for each of resource indexes (k),
wherein the phase-shift-based precoding matrix has a form of multiplication of a precoding matrix (P), a diagonal matrix (D) and an unitary matrix (U),
wherein the precoding matrix is cyclically selected from a codebook having (Nc) precoding matrixes using a modulo operation,
wherein the modulo operation is defined by using the resource index (k) and the (Nc).
11. The transceiver of claim 10 , wherein the phase-shift-based precoding matrix is represented by a following equation:
(
ℙ
N
t
×
R
)
(
ⅇ
jθ
1
k
0
…
0
0
ⅇ
jθ
2
k
…
0
⋮
⋮
⋱
⋮
0
0
…
ⅇ
jθ
R
k
)
(
𝕌
R
×
R
)
[
Equation
]
where ( N t ×R ) is the precoding matrix for the resource index (k), N t is a number of the multiple antennas, ( R×R ) is the unitary matrix, θ i is a phase angle value, and (R) corresponds to a spatial multiplexing rate.
12. The transceiver of claim 10 , wherein the resource index (k) is one of a subcarrier index and a virtual subcarrier index.