Patent ID: 7991058

Claim:
An OFDM (Orthogonal Frequency Division Multiplexing) reception device that receives an OFDM signal including a plurality of symbols, each symbol having inserted therein a guard interval signal, and demodulates the received OFDM signal by performing a FFT (Fast Fourier Transform) on a signal of an effective symbol length for each symbol, the OFDM reception device comprising: a detection unit operable to detect an impulse noise occurrence time at which impulse noise, whose amplitude is no less than a predetermined value, occurs in the received OFDM signal; and a FFT control unit operable to, if the impulse noise occurrence time is within a duration estimated to have the guard interval signal in a symbol or within a duration estimated to have a signal equivalent to the guard interval signal in the symbol, control the FFT to be performed using a value of a signal, among a plurality of signals included in the symbol, that is equivalent to a signal at the impulse noise occurrence time, as a substitute for a value of the signal at the impulse noise occurrence time, and wherein the FFT is performed by a FFT circuit, wherein the FFT control unit includes a FFT window determination unit operable to determine, for each symbol, a signal of the effective symbol length as a FFT window that is subjected to the FFT, and supply a signal that constitutes the FFT window to the FFT circuit, wherein the guard interval signal is identical to a latter portion of an effective symbol duration signal in transmission and is inserted before the effective symbol duration signal, and wherein the FFT window determination unit determines, as a start time of the FFT window, a time which is within the duration estimated to have the guard interval signal and which is a start time of a section, having the effective symbol length, in which a number of impulse noise occurrences equals 0, or has a minimum value.