| 摘要 |
PROBLEM TO BE SOLVED: To achieve carrier frequency synchronization with short lead-in time, and at the same time to eliminate the influence of phase fluctuation common to an entire sub carrier due to the phase noise of a tuner or the like in an OFDM signal demodulation device. SOLUTION: A differential detection circuit 26 allows the output of an FFT circuit 25 to be differentially detected between symbols, a correlation calculation circuit 27 calculates the correlation value between differential detection output and the arrangement information of the sub carrier for pilot transmission, a wideband carrier frequency error calculation circuit 28 calculates a frequency error in sub carrier interval units from the peak position of the correlation value, and a carrier frequency correction circuit 23 uses the frequency error for correcting a carrier frequency. Also, a phase averaging circuit 29 averages the phase of the differential detection output corresponding to the sub carrier for pilot transmission, and a phase fluctuation correction circuit 30 uses the averaged phase for correcting the phase fluctuation common to entire sub carriers.
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