Patent ID: 8433014

Claim:
A receiving apparatus for receiving an orthogonal frequency division multiplexing signal generated by adding K pieces (K<N) of data which is at the end of a signal of inverse discrete Fourier transform output as a guard interval to the head of a signal after mapping transmitted data of each sub-carrier at a signal point position in accordance with a predetermined modulation scheme and performing an inverse discrete Fourier transform of N points (N>M) in order to transmit transmitted data with M pieces of sub-carriers, said receiving apparatus comprising: a frequency transform part for transforming a frequency of said received signal to a desired frequency; a time axis data expansion part for extracting at least K+N pieces of data corresponding to one symbol including a guard interval from output of said frequency transform part to generate 2N pieces of data by adding zero before and after the extracted data; a window shaping part for shaping a waveform by multiplying output of said time axis data expansion part by a window coefficient; a discrete Fourier transform part for performing a discrete Fourier transform of 2N points with respect to output of said window shaping part; a demodulation part for performing a demodulation of sub-carriers by extracting transmitted sub-carrier components from output of said discrete Fourier transform part; an inter-carrier interference component calculation part for calculating an inter-carrier interference component, with the output of said discrete Fourier transform part as input; and a window coefficient generation part for selecting a window function on the basis of output of said inter-carrier interference component calculation part to output said window coefficient in accordance with the selected window function to said window shaping part, wherein said window coefficient generation part comprises a window coefficient table with the output of said inter-carrier interference component calculation part as input thereof, said window coefficient table storing a plurality of window coefficients in accordance with a size of inter-carrier interference, and a characteristic of a window function represented by each of said window coefficients stored in said window coefficient table has a gentler curve as the size of said inter-carrier interference gets larger.