A radio transmission apparatus determines information indicative of an estimated communications channel condition and generates a single modulation signal or a plurality of modulation signals based on the estimated communications channel condition information. The single modulation signal is transmitted from a first antenna of a plurality of antenna or the plurality of modulation signals are transmitted from the first antenna and at least a second antenna of the plurality of antenna. The plurality of modulation signals include different information from each other and are transmitted over an identical frequency band and 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.