Broadcast signal transmission method, broadcast signal transmission apparatus, broadcast signal reception method, and broadcast signal reception apparatus
Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a precoding weight by a baseband signal after a first mapping and a baseband signal after a second mapping and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.
1. A transmission method for a base station apparatus comprising:
generating control information indicating whether or not to execute a precoding process that regularly changes phase with respect to first modulated symbols s 1 and second modulated symbols s 2 ;
mapping the control information to control information symbols by using a mapper; and
transmitting the control information symbols from one or more antennas to a terminal apparatus, wherein
in a case of executing the precoding process, first symbols z 1 and second symbols z 2 to be transmitted from the one or more antennas to the terminal apparatus are generated by
applying the precoding process, by using a precoder, on the first modulated symbols s 1 and the second modulated symbols s 2 by using a matrix selected from among 2 matrices F[i] to generate the first symbols z 1 and the second symbols z 2 , i being equal to an integer 0 and 1; and
applying a transmission to the first symbols z 1 and the second symbols z 2 from the one or more antennas, wherein
the 2 matrices F[i] is regularly changing a phase of the first modulated symbols s 1 and a phase of the second modulated symbols s 2 ,
each of the 2 matrices F[i] is selected at least once in 2 symbols,
the first symbols z 1 and the second symbols z 2 satisfy (z 1 , z 2 ) T =F[i] (s 1 , s 2 ) T , and
the 2 matrices F[i] are expressed by the following equations:
F
[
i
]
=
1
2
(
e
j
0
e
j
0
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
)
θ
21
(
0
)
=
0
,
θ
21
(
1
)
=
π
2
.
2. A base station apparatus comprising:
control information generating circuitry that, in operation, generates control information indicating whether or not to execute a precoding process that regularly changes phase with respect to first modulated symbols s 1 and second modulated symbols s 2 ;
mapping circuitry that, in operation, maps the control information to control information symbols; and
transmission circuitry that, in operation, transmits the control information symbols from one or more antennas to a terminal apparatus, wherein
in a case of executing the precoding process, first symbols z 1 and second symbols z 2 to be transmitted to the terminal apparatus are generated by
applying the precoding process, by using a precoder, on the first modulated symbols s 1 and the second modulated symbols s 2 by using a matrix selected from among 2 matrices F[i] to generate the first symbols z 1 and the second symbols z 2 , i being equal to an integer 0 and 1; and
applying a transmission to the first symbols z 1 and the second symbols z 2 from the one or more antennas, wherein
the 2 matrices F[i] is regularly changing a phase of the first modulated symbols s 1 and a phase of the second modulated symbols s 2 ,
each of the 2 matrices F[i] is selected at least once in 2 symbols,
the first symbols z 1 and the second symbols z 2 satisfy (z 1 , z 2 ) T =F[i] (s 1 , s 2 ) T , and
the 2 matrices F[i] are expressed by the following equations:
F
[
i
]
=
1
2
(
e
j
0
e
j
0
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
)
θ
21
(
0
)
=
0
,
θ
21
(
1
)
=
π
2
.
3. A reception method for a terminal apparatus comprising:
receiving control information symbols and a plurality of data symbols with one or more antennas;
detecting, from the control information symbols, control information indicating whether or not a precoding process is executed with respect to a plurality of data symbols; and
applying a decoding process, by using a decoder, on the plurality of data symbols based on the detection result of the control information symbols, wherein
in a case of executing the precoding process, a base station apparatus generates first symbols z 1 and second symbols z 2 , to be transmitted from one or more antennas of the base station apparatus to the terminal apparatus, by
applying the precoding process, by using a precoder, on first modulated symbols s 1 and second modulated symbols s 2 by using a matrix selected from among 2 matrices F[i] to generate the first symbols z 1 and the second symbols z 2 , i being equal to an integer 0 and 1; and
applying a transmission to the first symbols z 1 and the second symbols z 2 from the one or more antennas of the base station apparatus, wherein
the 2 matrices F[i] is regularly changing a phase of the first modulated symbols s 1 and a phase of the second modulated symbols s 2 ,
each of the 2 matrices F[i] is selected at least once in 2 symbols,
the first symbols z 1 and the second symbols z 2 satisfy (z 1 , z 2 ) T =F[i] (s 1 , s 2 ) T , and
the 2 matrices F[i] are expressed by the following equations:
F
[
i
]
=
1
2
(
e
j
0
e
j
0
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
)
θ
21
(
0
)
=
0
,
θ
21
(
1
)
=
π
2
.
4. A terminal apparatus comprising:
reception circuitry that, in operation, receives control information symbols and a plurality of data symbols with one or more antennas;
detecting circuitry that, in operation, detects, from the control information symbols, control information indicating whether or not a precoding process is executed with respect to a plurality of data symbols; and
decoding circuitry that, in operation, applies a decoding process to the plurality of data symbols based on the detection result of the control information symbols, wherein
in a case of executing the precoding process, a base station apparatus generates first symbols z 1 and second symbols z 2 , to be transmitted from one or more antennas of the base station apparatus to the terminal apparatus, by
applying the precoding process, by using a precoder, on first modulated symbols s 1 and second modulated symbols s 2 by using a matrix selected from among 2 matrices F[i] to generate the first symbols z 1 and the second symbols z 2 , i being equal to an integer 0 and 1; and
applying a transmission to the first symbols z 1 and the second symbols z 2 from the one or more antennas of the base station apparatus, wherein
the 2 matrices F[i] is regularly changing a phase of the first modulated symbols s 1 and a phase of the second modulated symbols s 2 ,
each of the 2 matrices F[i] is selected at least once in 2 symbols,
the first symbols z 1 and the second symbols z 2 satisfy (z 1 , z 2 ) T =F[i] (s 1 , s 2 ) T , and
the 2 matrices F[i] are expressed by the following equations:
F
[
i
]
=
1
2
(
e
j
0
e
j
0
e
j
θ
21
(
i
)
e
j
(
θ
21
(
i
)
+
π
)
)
θ
21
(
0
)
=
0
,
θ
21
(
1
)
=
π
2
.