Transmission method and transmission apparatus

A transmission apparatus having four antennas comprising:

• a transmission and modulation scheme selector configured to select (i) a transmission scheme, for transmitting a plurality of transmission signals, among a plurality of transmission schemes according to a number of a plurality of antennas used for a transmission, and (ii) a modulation scheme among a plurality of modulation schemes according to the number of a plurality of antennas used for a transmission;
• a modulator configured to modulate the plurality of transmission signals using the selected modulation scheme and to output a plurality of modulated transmission signals;
• and
• a transmitter configured to transmit the plurality of modulated transmission signals using the plurality of antennas used for the transmission among the four antennas, wherein:
• the transmission and modulation scheme selector is configured to:
• select, when the four antennas are used for the transmission, a modulating scheme in which a maximum value of a number of modulated M-ary index of the selected modulation scheme is smaller than a maximum value of a number of modulated M-ary index of the modulation scheme selected when two antennas among the four antennas are used for the transmission, and
• select, when the two antennas are used for the transmission, a modulating scheme having a same maximum value of a number of modulated M-ary index for every selected transmission scheme.