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.