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 physical layer pipes (PLPs) and transmitting the plurality of PLPs from a plurality of antennas in the same frequency at the same time, the transmission method comprising, in the generation of the plurality of PLPs:
generating the plurality of PLPs, the plurality of PLPs each including a plurality of modulated symbols;
selecting one matrix from among N matrices F[i] for each of a plurality of symbols by hopping between the matrices, 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 symbols; and
generating first precoded signal z1(p) and second precoded signal z2(p) by precoding first baseband symbols s1(p) and second baseband symbols s2(p) by using the selected one of the N matrices F[i], both the first baseband symbols s1(p) and the second baseband symbols s2(p) being symbols included in a p-th one of the PLPs, p being an integer 1 or greater and no greater than q, q being an integer 2 or greater, wherein
the first precoded signal z1(p) and the second precoded signal z2(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
j
θ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
j
θ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number, and 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 same one of the N matrices F[i] is used for a first symbol of the first baseband symbols s1(p) and a first symbol of the second baseband symbols s2(p).
2. A transmission apparatus for generating a plurality of physical layer pipes (PLPs) and transmitting the plurality of PLPs from a plurality of antennas in the same frequency at the same time, the transmission apparatus comprising:
a PLP generating unit that generates the plurality of PLPs, the plurality of PLPs each including a plurality of modulated symbols;
a weighting information generating unit that selects one matrix from among N matrices F[i] for each of a plurality of symbols by hopping between the matrices, 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 symbols; and
a weighting unit that generates first precoded signal z1(p) and second precoded signal z2(p) by precoding first baseband symbols s1(p) and second baseband symbols s2(p) by using the selected one of the N matrices F[i], both the first baseband symbols s1(p) and the second baseband symbols s2(p) being symbols included in a p-th one of the PLPs, p being an integer 1 or greater and no greater than q, q being an integer 2 or greater, wherein
the first precoded signal z1(p) and the second precoded signal z2(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, and 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 same one of the N matrices F[i] is used for a first symbol of the first baseband symbols s1(p) and a first symbol of the second baseband symbols s2(p).
3. A reception method comprising the step of:
receiving a received signal obtained by receiving a plurality of physical layer pipes (PLPs) transmitted from a plurality of antennas in the same frequency at the same time;
demodulating the received PLPs by using a predetermined modulation scheme to obtain a demodulated signal, wherein
a p-th one of the PLPs includes first precoded signal z1(p) and second precoded signal z2(p), p being an integer 1 or greater and no greater than q, q being an integer 2 or greater,
the first precoded signal z1(p) and the second precoded signal z2(p) are generated by precoding first baseband symbols s1(p) and second baseband symbols s2(p) by using a selected matrix,
for each of a plurality of symbols, the selected matrix is one matrix selected from among N matrices F[i] by hopping between the matrices, 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 precoded signal z1(p) and the second precoded signal z2(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
j
θ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
j
θ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number, and 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 same one of the N matrices F[i] is used for a first symbol of the first baseband symbols s1(p) and a first symbol of the second baseband symbols s2(p).
4. A reception apparatus comprising:
a signal receiving unit that receives a received signal obtained by receiving a plurality of physical layer pipes (PLPs) transmitted from a plurality of antennas in the same frequency at the same time;
a demodulating unit that demodulates the received PLPs by using a predetermined modulation scheme to obtain a demodulated signal, wherein
a p-th one of the PLPs includes first precoded signal z1(p) and second precoded signal z2(p), p being an integer 1 or greater and no greater than q, q being an integer 2 or greater,
the first precoded signal z1(p) and the second precoded signal z2(p) are generated by precoding first baseband symbols s1(p) and second baseband symbols s2(p) by using a selected matrix,
for each of a plurality of symbols, the selected matrix is one matrix selected from among N matrices F[i] by hopping between the matrices, 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 precoded signal z1(p) and the second precoded signal z2(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
j
θ
11
(
i
)
α
×
ⅇ
j
(
θ
11
(
i
)
+
λ
)
α
×
ⅇ
j
θ
21
(
i
)
ⅇ
j
(
θ
21
(
i
)
+
λ
+
π
)
)
where λ represents an arbitrary angle, α represents a positive real number, and 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 same one of the N matrices F[i] is used for a first symbol of the first baseband symbols s1(p) and a first symbol of the second baseband symbols s2(p).