A radio transmission apparatus performs communications with high transmission efficiency. In this apparatus, a modulator modulates data and outputs to a first spreader. A second modulator modulates data under a modulation scheme having a higher M-ary number than the first modulator and outputs the modulated data to a second spreader. The first spreader spreads the data and outputs the spread data to a frequency domain mapping section. The second spreader spreads the data and outputs the spread data to a time domain mapping section. A frequency domain mapping section maps chips with spread data on subcarriers in the frequency domain and outputs the data with chips mapped on subcarriers to an IFFT section. The time domain mapping section maps chips with spread data on subcarriers in the time domain and outputs the data with chips mapped on subcarriers to the IFFT section.