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 method for generating a plurality of precoded signals and transmitting the plurality of precoded signals from a plurality of antennas in the same frequency at the same time, the transmission method comprising, in the generation of the plurality of precoded signals, the steps of:
selecting one matrix from among N matrices F[i] by hopping between the matrices, for each of a plurality of slots, where i is an integer no less than 0 and no more than N−1, and N is an integer 3 or greater, the N matrices F[i] each defining a precoding process that is performed on a plurality of baseband signals;
generating a first baseband signal s 1 (p) and a second baseband signal s 2 (p) from a p-th transmission data group by using a predetermined error correction block coding scheme, p being an integer 1 or greater and no greater than q, q being an integer 2 or greater; and
generating a first precoded signal z 1 (p) and a second precoded signal z 2 (p) by precoding the first baseband signal s 1 (p) and the second baseband signal s 2 (p) by using the selected one of the N matrices F[i], wherein
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) satisfy:
( z 1( p ), z 2( p )) T =F[i ]( s 1( p ), s 2( p )) T ,
the N matrices F[i] satisfy:
F
[
i
]
=
1
α
2
+
1
(
ⅇ
jθ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
jθ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number other than 1, θ 11 (i) and θ 21 (i) satisfy:
e j(θ 11 (x)−θ 21 (x)) ≠e j(θ 11 (y)−θ 21 (y))
where x and y are any integers no less than 0 and no more than N−1 and satisfy x≠y,
and
a first slot of the first baseband signal s 1 (p) and a first slot of the second baseband signal s 2 (p) use a same one of the N matrices F[i].
2. A transmission apparatus for generating a plurality of precoded signals and transmitting the plurality of precoded signals from a plurality of antennas in the same frequency at the same time, the transmission apparatus comprising:
a weighting information generating unit that selects one matrix from among N matrices F[i] by hopping between the matrices, for each of a plurality of slots, where i is an integer no less than 0 and no more than N−1, and N is an integer 3 or greater, the N matrices F[i] each defining a precoding process that is performed on a plurality of baseband signals;
an error correction coding unit that generates a first baseband signal s 1 (p) and a second baseband signal s 2 (p) from a p-th transmission data group by using a predetermined error correction block coding scheme, p being an integer 1 or greater and no greater than q, q being an integer 2 or greater;
a weighting unit that generates a first precoded signal z 1 (p) and a second precoded signal z 2 (p) by precoding the first baseband signal s 1 (p) and the second baseband signal s 2 (p) by using the selected one of the N matrices F[i], wherein
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) satisfy:
( z 1( p ), z 2( p )) T =F[i ]( s 1( p ), s 2( p )) T ,
the N matrices F[i] satisfy:
F
[
i
]
=
1
α
2
+
1
(
ⅇ
jθ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
jθ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number other than 1, θ 11 (i) and θ 21 (i) satisfy:
e j(θ 11 (x)−θ 21 (x)) ≠e j(θ 11 (y)−θ 21 (y))
where x and y are any integers no less than 0 and no more than N−1 and satisfy x≠y, and
a first slot of the first baseband signal s 1 (p) and a first slot of the second baseband signal s 2 (p) use a same one of the N matrices F[i].
3. A reception method comprising the step of:
receiving a received signal obtained by receiving a plurality of signals transmitted from a plurality of antennas in the same frequency at the same time;
demodulating the received signal by using a predetermined modulation method to obtain a demodulated signal, wherein
the plurality of signals include a first precoded signal z 1 (p) and a second precoded signal z 2 (p), p being an integer 1 or greater and no greater than q, q being an integer 2 or greater,
the first precoded signals z 1 (p) and the second precoded signals z 2 (p) are generated by precoding a first baseband signal s 1 (p) and a second baseband signal s 2 (p) by using a selected matrix,
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) are generated from a p-th transmission data group by using a predetermined error correction block coding scheme,
the selected matrix is one matrix selected from among N matrices F[i] by hopping between the matrices, for each of a plurality of slots, where i is an integer no less than 0 and no more than N−1, and N is an integer 3 or greater,
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) satisfy:
( z 1( p ), z 2( p )) T =F[i ]( s 1( p ), s 2( p )) T ,
the N matrices F[i] satisfy:
F
[
i
]
=
1
α
2
+
1
(
ⅇ
jθ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
jθ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number other than 1, θ 11 (i) and θ 21 (i) satisfy:
e j(θ 11 (x)−θ 21 (x)) ≠e j(θ 11 (y)−θ 21 (y))
where x and y are any integers no less than 0 and no more than N−1 and satisfy x≠y,
and
a first slot of the first baseband signal s 1 (p) and a first slot of the second baseband signal s 2 (p) use a same one of the N matrices F[i].
4. A reception apparatus comprising:
a signal receiving unit that receives a received signal obtained by receiving a plurality of signals transmitted from a plurality of antennas in the same frequency at the same time;
a demodulating unit that demodulates the received signal by using a predetermined modulation method to obtain a demodulated signal, wherein
the plurality of signals include a first precoded signal z 1 (p) and a second precoded signal z 2 (p), p being an integer 1 or greater and no greater than q, q being an integer 2 or greater,
the first precoded signals z 1 (p) and the second precoded signals z 2 (p) are generated by precoding a first baseband signal s 1 (p) and a second baseband signal s 2 (p) by using a selected matrix,
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) are generated from a p-th transmission data group by using a predetermined error correction block coding scheme,
the selected matrix is one matrix selected from among N matrices F[i] by hopping between the matrices, for each of a plurality of slots, where i is an integer no less than 0 and no more than N−1, and N is an integer 3 or greater,
the first baseband signal s 1 (p) and the second baseband signal s 2 (p) satisfy:
( z 1( p ), z 2( p )) T =F[i ]( s 1( p ), s 2( p )) T ,
the N matrices F[i] satisfy:
F
[
i
]
=
1
α
2
+
1
(
ⅇ
jθ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
jθ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number other than 1, θ 11 (i) and θ 21 (i) satisfy:
e j(θ 11 (x)−θ 21 (x)) ≠e j(θ 11 (y)−θ 21 (y))
where x and y are any integers no less than 0 and no more than N−1 and satisfy x≠y,
and
a first slot of the first baseband signal s 1 (p) and a first slot of the second baseband signal s 2 (p) use a same one of the N matrices F[i].