Ofdm demodulation apparatus

摘要

An OFDM demodulation ( 1 ) is provided which includes a guard correlation/peak time detection circuit ( 12 ) to generate a peak timing Np of a guard interval correlation value, and a timing synchronization circuit ( 13 ) to estimate a symbol-boundary time Nx from the peak timing Np. The timing synchronization circuit ( 13 ) calculates the symbol-boundary time Nx by filtering the peak time Np by a DLL (delay locked loop) filter ( 43 ). Further, the DLL filter ( 43 ) includes a limiter ( 52 ) to limit the range of phase-error component and an asymmetric gain circuit ( 53 ) to change the magnitude of the gain correspondingly to the polarity of the phase error to prevent the timing from being pulled out due to a fading or multipath.