DEMODULATION METHOD AND DEMODULATOR

摘要

PROBLEM TO BE SOLVED: To obtain a correct demodulation signal by estimating timewise fluctuation in a phase caused by a phase error and a frequency error at a high speed in the case of phase synchronization detection by the quasi-synchronization detection system. SOLUTION: An optimum phase estimate circuit 8 estimates an optimum phase compensation amount H based on a received tentative demodulation signal U, a confirmative demodulation signal V and an optimum frequency compensation amount F by taking phase fluctuation due to a frequency error into account. Then a phase fluctuation estimate circuit 9 estimates the optimum frequency compensation amount based on fluctuation of a predetermined period of the optimum phase compensation amount H. A complex multiplier 7 applies complex multiplication to the tentative demodulation signal U and the optimum phase compensation amount H to completely eliminate a phase error due to the frequency error and to obtain a correct demodulation signal V.