A radio transmission apparatus includes a first antenna, a second antenna, and circuitry configured, based on information associated with an estimated communications channel condition, to generate a single modulation signal or a plurality of modulation signals based on the estimated communications channel condition information, and to (i) transmit the single modulation signal from the first antenna or (ii) transmit the plurality of modulation signals which include different information from each other over an identical frequency band from the first antenna and the second antenna at an identical temporal point. The single modulation signal and the plurality of modulation signals contain parameter information indicating a number of modulation signals transmitted at the same time.