DEMODULATION CIRCUIT FOR MULTICARRIER MODULATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a demodulation circuit provided with a phase tracking circuit capable of highly accurately detecting and correcting a phase rotation caused by a residual carrier frequency error or phase noise in a demodulation circuit for multicarrier modulation system for demodulating a multicarrier signal in a digital radio communication system. SOLUTION: A phase noise estimating means for estimating phase noise power on the basis of the phase rotation with a phase rotating signal being an output signal from a phase rotation detecting means as an entry and a filter control means for outputting a control signal for controlling a filter means on the basis of an estimated phase noise value being an output signal from the phase noise estimating means with such a value as an entry are separately provided to the demodulation circuit and the filter means varies characteristics. According to the control signal of the filter control means, the characteristics are changed corresponding to the phase noise power.