Transmission method, transmission device, reception method and reception device
View Patent ↗A transmission method includes mapping processing, phase change processing, and transmission processing. In the mapping processing, a plurality of first modulation signals and a plurality of second modulation signals are generated using a first mapping scheme, and a plurality of third modulation signals and a plurality of fourth modulation signals are generated using a second mapping scheme. In the phase change processing, a phase change is performed on the plurality of second modulation signals and the plurality of fourth modulation signals using all N kinds of phases. In the transmission processing, the first modulation signals and the second modulation signals are respectively transmitted at a same frequency and a same time from different antennas, and the third modulation signals and the fourth modulation signals are respectively transmitted at a same frequency and a same time from the different antennas.
1. A transmission method comprising:
first generating processing of generating a first orthogonal frequency division modulated (OFDM) symbol including a plurality of first modulated signals s 1 ( k ) and a second OFDM symbol including a plurality of second modulated signals s 2 ( k ),
k denoting carrier number and k=0, 1, . . . , K,
each of the plurality of first modulated signals s 1 ( k ) corresponding to any one of 16 signal points comprised in a first mapping scheme,
the second modulated signal s 2 ( k ) being equal to the first modulated signal s 1 ( k ) for each of the carrier number k,
first phase change processing of performing a first phase change on the plurality of second modulated signals s 2 ( k ) using amounts of the first phase change specified by a function of the carrier number k,
first transmission processing of transmitting the plurality of first modulated signals s 1 ( k ) using a first antenna and transmitting the plurality of second modulated signals s 2 ( k ) using a second antenna,
the first modulated signal s 1 ( k ) and the second modulated signal s 2 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
second generating processing of generating a third OFDM symbol including a plurality of third modulated signals s 3 ( k ) and a fourth OFDM symbol including a plurality of fourth modulated signals s 4 ( k ),
each of the plurality of third modulated signals s 3 ( k ) corresponding to any one of 16 signal points comprised in a second mapping scheme,
the first mapping scheme and the second mapping scheme being different from each other in a signal point arrangement;
the fourth modulated signal s 4 ( k ) being equal to the third modulated signal s 3 ( k ) for each of the carrier number k,
second phase change processing of performing a second phase change on the plurality of fourth modulated signals s 4 ( k ) using amounts of the second phase change specified by the function of the carrier number k, and
second transmission processing of transmitting the plurality of third modulated signals s 3 ( k ) using the first antenna and transmitting the plurality of fourth modulated signals s 4 ( k ) using the second antenna,
the third modulated signal s 3 ( k ) and the fourth modulated signal s 4 ( k ) are transmitted at same frequency and same time for each of the carrier number k.
2. A transmission system comprising:
generating circuitry which, in operation,
generates a first orthogonal frequency division modulated (OFDM) symbol including a plurality of first modulated signals s 1 ( k ) and a second OFDM symbol including a plurality of second modulated signals s 2 ( k ),
k denoting carrier number and k=0, 1, . . . , K,
each of the plurality of first modulated signals s 1 ( k ) corresponding to any one of 16 signal points comprised in a first mapping scheme,
the second modulated signal s 2 ( k ) being equal to the first modulated signal s 1 ( k ) for each of the carrier number k, and
generates a third OFDM symbol including a plurality of third modulated signals s 3 ( k ) and a fourth OFDM symbol including a plurality of fourth modulated signals s 4 ( k ),
each of the plurality of third modulated signals s 3 ( k ) corresponding to any one of 16 signal points comprised in a second mapping scheme,
the first mapping scheme and the second mapping scheme being different from each other in a signal point arrangement;
the fourth modulated signal s 4 ( k ) being equal to the third modulated signal s 3 ( k ) for each of the carrier number k,
phase change circuitry which, in operation,
performs a first phase change on the plurality of second modulated signals s 2 ( k ) using amounts of the first phase change specified by a function of the carrier number k, and
performs a second phase change on the plurality of fourth modulated signals s 4 ( k ) using amounts of the second phase change specified by the function of the carrier number k,
first transmission circuitry which, in operation,
transmits the plurality of first modulated signals s 1 ( k ) using a first antenna, and
transmits the plurality of third modulated signals s 3 ( k ) using the first antenna, and
second transmission circuitry which, in operation,
transmits the plurality of second modulated signals s 2 ( k ) using a second antenna and
transmits the plurality of fourth modulated signals s 4 ( k ) using the second antenna,
the first modulated signal s 1 ( k ) and the second modulated signal s 2 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
the third modulated signal s 3 ( k ) and the fourth modulated signal s 4 ( k ) are transmitted at same frequency and same time for each of the carrier number k.
3. A reception method comprising:
first reception processing of receiving a first reception symbol obtained by receiving a first orthogonal frequency division modulated (OFDM) symbol transmitted from a first antenna of a transmission system and a second OFDM symbol transmitted from a second antenna of the transmission system,
the first OFDM symbol carrying a plurality of first modulated signals s 1 ( k ),
the second OFDM symbol carrying a plurality of second modulated signals s 2 ( k ),
k denoting carrier number and k=0, 1, . . . , K,
the first modulated signal s 1 ( k ) and the second modulated signal s 2 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
each of the plurality of first modulated signals s 1 ( k ) corresponding to any one of 16 signal points comprised in a first mapping scheme,
the second modulated signal s 2 ( k ) being equal to the first modulated signal s 1 ( k ) for each of the carrier number k,
the plurality of second modulated signals s 2 ( k ) being subjected to a first phase change using amounts of the first phase change specified by a function of the carrier number k before transmission,
first demodulation processing of demodulating the first reception symbol using a first de-mapping scheme corresponding to the first mapping scheme,
second reception processing of receiving a second reception symbol obtained by receiving a third OFDM symbol transmitted from the first antenna of the transmission system and a fourth OFDM symbol transmitted from the second antenna of the transmission system,
the third OFDM symbol carrying a plurality of third modulated signals s 3 ( k ),
the fourth OFDM symbol carrying a plurality of fourth modulated signals s 4 ( k ),
the third modulated signal s 3 ( k ) and the fourth modulated signal s 4 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
each of the plurality of third modulated signals s 3 ( k ) corresponding to any one of 16 signal points comprised in a second mapping scheme,
the first mapping scheme and the second mapping scheme being different from each other in a signal point arrangement;
the fourth modulated signal s 4 ( k ) being equal to the third modulated signal s 3 ( k ) for each of the carrier number k,
the plurality of fourth modulated signals s 4 ( k ) being subjected to a second phase change using amounts of the second phase change specified by the function of the carrier number k before transmission,
second demodulation processing of demodulating the second reception symbol using a second de-mapping scheme corresponding to the second mapping scheme.
4. A reception device comprising:
reception circuitry which, in operation,
receives a first reception symbol obtained by receiving a first orthogonal frequency division modulated (OFDM) symbol transmitted from a first antenna of a transmission system and a second OFDM symbol transmitted from a second antenna of the transmission system,
the first OFDM symbol carrying a plurality of first modulated signals s 1 ( k ),
the second OFDM symbol carrying a plurality of second modulated signals s 2 ( k ),
k denoting carrier number and k=0, 1, . . . , K,
the first modulated signal s 1 ( k ) and the second modulated signal s 2 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
each of the plurality of first modulated signals s 1 ( k ) corresponding to any one of 16 signal points comprised in a first mapping scheme,
the second modulated signal s 2 ( k ) being equal to the first modulated signal s 1 ( k ) for each of the carrier number k,
the plurality of second modulated signals s 2 ( k ) being subjected to a first phase change using amounts of the first phase change specified by a function of the carrier number k before transmission,
receives a second reception symbol obtained by receiving a second reception symbol obtained by receiving a third OFDM symbol transmitted from the first antenna of the transmission system and a fourth OFDM symbol transmitted from the second antenna of the transmission system,
the third OFDM symbol carrying a plurality of third modulated signals s 3 ( k ),
the fourth OFDM symbol carrying a plurality of fourth modulated signals s 4 ( k ),
the third modulated signal s 3 ( k ) and the fourth modulated signal s 4 ( k ) are transmitted at same frequency and same time for each of the carrier number k,
each of the plurality of third modulated signals s 3 ( k ) corresponding to any one of 16 signal points comprised in a second mapping scheme,
the first mapping scheme and the second mapping scheme being different from each other in a signal point arrangement;
the fourth modulated signal s 4 ( k ) being equal to the third modulated signal s 3 ( k ) for each of the carrier number k,
the plurality of fourth modulated signals s 4 ( k ) being subjected to a second phase change using amounts of the second phase change specified by the function of the carrier number k before transmission, and
demodulation circuitry which, in operation,
demodulates the first reception symbol using a first de-mapping scheme corresponding to the first mapping scheme, and
demodulates the second reception symbol using a second de-mapping scheme corresponding to the second mapping scheme.