Transmission method, transmitter apparatus, reception method and receiver apparatus

A transmission method comprising:

• generating a first modulation signal s1 by using a first modulation scheme;
• generating a second modulation signal s2 by using a second modulation scheme;
• regularly switching between a plurality of precoding matrices for generating a first precoded signal z1 and a second precoded signal z2;
• generating the first precoded signal z1 and the second precoded signal z2 by applying one of the plurality of precoding matrices to the first modulation signal s1 and the second modulation signal s2;
• transmitting the first precoded signal z1 from one or more first antennas;
• and
• transmitting the second precoded signal z2 from one or more second antennas, the second antennas being different from the first antennas, wherein
• the first precoded signal z1 includes a first symbol and a second symbol that is adjacent to the first symbol in a frequency domain,
• the second precoded signal z2 includes a third symbol and a fourth symbol that is adjacent to the third symbol in the frequency domain,
• the first symbol and the third symbol are transmitted at a first frequency,
• the second symbol and the fourth symbol are transmitted at a second frequency, and
• a first precoding matrix for the first symbol and the third symbol and a second precoding matrix for the second symbol and the fourth symbol are different from each other.

A transmission device comprising:

• a modulation unit generating a first modulation signal s1 by using a first modulation scheme, and generating a second modulation signal s2 by using a second modulation scheme;
• a precoding weight generation unit regularly switching between a plurality of precoding matrices for generating a first precoded signal z1 and a second precoded signal z2, and
• a weighting unit generating the first precoded signal z1 and the second precoded signal z2 by applying one of the plurality of precoding matrices to the first modulation signal s1 and the second modulation signal s2;
• and
• a transmission unit transmitting the first precoded signal z1 from one or more first antennas, and transmitting the second precoded signal z2 from one or more second antennas, the second antennas being different from the first antennas, wherein
• the weighting unit generates the first precoded signal z1 that includes a first symbol and a second symbol that is adjacent to the first symbol in a frequency domain, and generates the second precoded signal z2 that includes a third symbol and a fourth symbol that is adjacent to the third symbol in the frequency domain,
• the transmission unit transmits the first symbol and the third symbol at a first frequency and the second symbol and the fourth symbol at a second frequency, and
• the precoding weight generation unit switches a first precoding matrix for the first symbol and the third symbol to a second precoding matrix for the second symbol and the fourth symbol, the first precoding matrix and the second precoding matrix being different from each other.

A reception method comprising:

• receiving, by using one or more antennas, a signal including a first transmission signal z1 and a second transmission signal z2 precoded and transmitted from a transmission device;
• demodulating the received signal by using a demodulation scheme corresponding to one or more predetermined modulation schemes;
• and
• obtaining data from the demodulated signal by performing predetermined error-correction decoding, wherein
• the first transmission signal z1 and the second transmission signal z2 are signals generated by applying a precoding matrix to a first modulation signal s1 and a second modulation signal s2, the precoding matrix being regularly switched between a plurality of precoding matrices, the first modulation signal s1 being a signal modulated by using a first modulation scheme from among the one or more predetermined modulation schemes, the second modulation signal s2 being a signal modulated by using a second modulation scheme from among the one or more predetermined modulation schemes,
• the first transmission signal z1 includes a first symbol and a second symbol that is adjacent to the first symbol in a frequency domain,
• the second transmission signal z2 includes a third symbol and a fourth symbol that is adjacent to the third symbol in the frequency domain,
• the first symbol and the third symbol are transmitted at a first frequency,
• the second symbol and the fourth symbol are transmitted at a second frequency, and
• a first precoding matrix for the first symbol and the third symbol and a second precoding matrix for the second symbol and the fourth symbol are different from each other.

A reception device comprising:

• a reception unit receiving, by using one or more antennas, a signal including a first transmission signal z1 and a second transmission signal z2 precoded and transmitted from a transmission device;
• a demodulation unit demodulating the received signal by using a demodulation scheme corresponding to one or more predetermined modulation schemes;
• and
• an error correction unit obtaining data from the demodulated signal by performing predetermined error-correction decoding, wherein
• the first transmission signal z1 and the second transmission signal z2 are signals generated by applying a precoding matrix to a first modulation signal s1 and a second modulation signal s2, the precoding matrix being regularly switched between a plurality of precoding matrices, the first modulation signal s1 being a signal modulated by using a first modulation scheme from among the one or more predetermined modulation schemes, the second modulation signal s2 being a signal modulated by using a second modulation scheme from among the one or more predetermined modulation schemes,
• the first transmission signal z1 includes a first symbol and a second symbol that is adjacent to the first symbol in a frequency domain,
• the second transmission signal z2 includes a third symbol and a fourth symbol that is adjacent to the third symbol in the frequency domain,
• the first symbol and the third symbol are transmitted at a first frequency,
• the second symbol and the fourth symbol are transmitted at a second frequency, and
• a first precoding matrix for the first symbol and the third symbol and a second precoding matrix for the second symbol and the fourth symbol are different from each other.