| 摘要 |
PROBLEM TO BE SOLVED: To provide frequency offset/OFDM symbol detectors adaptable to a large frequency offset not less than one carrier wave in an OFDM signal. SOLUTION: There are provided: a multiplication circuit 30 multiplying a reception signal R generated by performing Fourier transformation to an OFDM modulated signal, where pilot symbols are arranged dispersedly in accordance with four kinds of patterns for periodical transmission, by a pseudorandom number bit sequence W; four arithmetic circuits 40 that extract the pilot symbols corresponding to each pattern from a multiplication result R×W of the multiplication circuit 30 for each of the four kinds of patterns and calculate the sum of phase differences among the extracted pilot symbols to output an absolute value ¾V¾; a detection circuit 50 detecting a frequency offset OFF based on the maximum value of the absolute values ¾V¾ calculated by the four arithmetic circuits 40. A complex sinusoidal wave SIN is generated based on the detected frequency offset OFF, and the frequency of an input signal IN is converted, thus correcting the offset of the reception signal R. COPYRIGHT: (C)2008,JPO&INPIT
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