A disclosed transmission apparatus comprises a switching portion that switches radio access methods; a frequency domain signal generation portion that allocates a radio resource to a spread chip sequence on which one of a fast Fourier transformation and a series/parallel conversion is performed in accordance with the switched radio accessed method, so as to generate a signal in a frequency domain; and a transmission signal generation portion that performs a fast inverse Fourier transformation on the signal in the frequency domain so as to generate a transmission signal.