Precoding method, precoding device
Disclosed is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals that are transmitted in the same frequency bandwidth at the same time. According to the precoding method, one matrix is selected from among matrices defining a precoding process that is performed on the plurality of baseband signals by hopping between the matrices. A first baseband signal and a second baseband signal relating to a first coded block and a second coded block generated by using a predetermined error correction block coding scheme satisfy a given condition.
1. A transmission apparatus comprising:
encoding circuitry, which in operation, encodes a transmission data sequence to two encoded data sequences that are to be decoded by a reception apparatus;
modulation circuitry, which in operation, modulates the two encoded data sequences to two modulated symbol sequences;
precoding circuitry, which in operation, precodes the two modulated symbol sequences by using a precoding matrix expressed by Math. 1 to generate two precoded symbol sequences;
F
[
i
]
=
1
2
[
1
1
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
]
Math
.
1
Orthogonal Frequency Division Multiplexing (OFDM) signal generation circuitry, which in operation, inverse fourier transforms the two precoded symbol sequences to two OFDM signals; and
transmission circuitry, which in operation, transmits the two OFDM signals from different antennas, wherein
in Math. 1, i is an integer that is zero or greater and varies for each modulated symbol, and θ 21 satisfies Math. 2,
e
j
θ
21
(
1
)
e
j
θ
21
(
0
)
=
e
j
(
π
2
)
.
Math
.
2
2. A transmission method comprising:
encoding a transmission data sequence to two encoded data sequences that are to be decoded by a reception apparatus;
modulating the two encoded data sequences to two modulated symbol sequences;
precoding the two modulated symbol sequences by using a precoding matrix expressed by Math. 3 to generate two precoded symbol sequences;
F
[
i
]
=
1
2
[
1
1
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
]
Math
.
3
Inverse Fourier Transforming the two precoded symbol sequences to two Orthogonal Frequency Division Multiplexing (OFDM) signals; and
transmitting the two OFDM from different antennas, wherein
in Math. 3, i is an integer that is zero or greater and varies for each modulated symbol, and θ 21 satisfies Math. 4,
e
j
θ
21
(
1
)
e
j
θ
21
(
0
)
=
e
j
(
π
2
)
.
Math
.
4
3. A reception device comprising:
reception circuitry, which in operation, receives signals including two Orthogonal Frequency Division Multiplexing (OFDM) signals transmitted from different antennas of a transmission apparatus;
decoding circuitry, which in operation, decodes the received signals to a transmission data sequence, wherein
the two OFDM signals are transmitted from the transmission apparatus through processing including:
encoding the transmission data sequence to the two encoded data sequences;
modulating the two encoded data sequences to two modulated symbol sequences;
precoding the two modulated symbol sequences by using a precoding matrix expressed by Math. 5 to generate two precoded symbol sequences;
F
[
i
]
=
1
2
[
1
1
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
]
Math
.
5
Inverse Fourier Transforming the two precoded symbol sequences to the two OFDM signals; and
transmitting the two OFDM signals from the different antennas,
in Math. 5, i is an integer that is zero or greater and varies for each modulated symbol, and θ 21 satisfies Math. 6,
e
j
θ
21
(
1
)
e
j
θ
21
(
0
)
=
e
j
(
π
2
)
.
Math
.
6
4. A reception method comprising:
receiving signals including two Orthogonal Frequency Division Multiplexing (OFDM) signals transmitted from different antennas of a transmission apparatus;
decoding the received signals to a transmission data sequence, wherein
the two OFDM signals are transmitted from the transmission apparatus through processing including:
encoding the transmission data sequence to the two encoded data sequences;
modulating the two encoded data sequences to two modulated symbol sequences;
precoding the two modulated symbol sequences by using a precoding matrix expressed by Math. 7 to generate two precoded symbol sequences;
F
[
i
]
=
1
2
[
1
1
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
]
Math
.
7
Inverse Fourier Transforming the two precoded symbol sequences to the two OFDM signals; and
transmitting the two OFDM signals from the different antennas, in Math. 7, i is an integer that is zero or greater and varies for each modulated symbol, and θ 21 satisfies Math. 8,
e
j
θ
21
(
1
)
e
j
θ
21
(
0
)
=
e
j
(
π
2
)
.
Math
.
8