An FFT unit generates a frequency domain signal by converting an OFDM signal using Fourier transform. A delay amount calculation unit generates a delay profile of the OFDM signal. The control determination unit detects a main wave and an interference wave using the delay profile. When the time difference between the main wave and a preceding wave is larger than a guard interval of the OFDM signal, an FFT window control unit sets the start position of the FFT window at a position shifted forward from the symbol start position of the main wave by an amount corresponding to the guard interval.