1. A wireless communication apparatus comprising: a first transformation value calculating unit that calculates three transformation values continuous in a frequency domain from N data values (N is an integer equal to or greater than one) by using a discrete Fourier transform equation that is used to transform the N data values continuous in a time domain into N transformation values continuous in the frequency domain; a phase difference calculating unit that obtains a change in a phase difference, which is a fixed value, from the three transformation values calculated by the first transformation value calculating unit and that calculates, on the basis of the obtained change in the phase difference, the phase difference between a calculated transformation value and a not-yet calculated transformation value; a second transformation value calculating unit that sequentially calculates the not-yet calculated transformation value by multiplying the calculated transformation value by a twiddle factor that uses the phase difference calculated by the phase difference calculating unit as a rotation angle; and a transmitting unit that maps, onto subcarriers, the transformation values calculated by the first transformation value calculating unit and the transformation values calculated by the second transformation value calculating unit, that performs an inverse Fourier transformation process on the mapped transformation values, and that transmits the transformation values subjected to the inverse Fourier transformation process.