A communication apparatus includes a plurality of transmitting units that transmit a signal stream from each different antenna; a scheduling unit being configured such that the number of outputs is set so as to not exceed the number of transmitting units capable of transmitting, and a combination of transmitting units corresponding to the number of outputs, to each of which one of the signal streams is to be input, is defined in the form of a precoding matrix; a codeword generating unit that generates, from data to be transmitted, a predetermined number of codewords to be transmitted out simultaneously; an encoder that generates, from the codewords, signal streams corresponding to the number of outputs; and a modulation unit that supplies each of the signal streams to a corresponding one of the transmitting units in accordance with the precoding matrix.