Orthogonal frequency division multiplex signal demodulator unit and orthogonal frequency division multiplex signal demodulating method

摘要

PROBLEM TO BE SOLVED: To allow the orthogonal frequency division multiplex signal demodulator to realize carrier frequency synchronization in a short locking time and to eliminate the effect of phase fluctuation in common to all subcarriers due to phase noise or the like of a tuner. ;SOLUTION: A differential detection circuit 26 applies inter-symbol differential detection to an output of an FFT circuit 25, a correlation calculation circuit 27 calculates a correlation between a differential detection output and arrangement information of a pilot transmission subcarrier, a broad band carrier frequency error calculation circuit 28 calculates a frequency error in the unit of subcarrier interval from a peak position of a correlation value and a carrier frequency correction circuit 23 corrects a carrier frequency by using it. Furthermore, a phase averaging circuit 29 averages phases of differential detection outputs corresponding to the pilot transmission subcarrier and phase fluctuation correction circuit 30 corrects phase fluctuation in common to all subcarriers by using it.;COPYRIGHT: (C)1999,JPO