Patent ID: 8867677

Claim:
A demodulation device comprising: a demodulation unit demodulating an input signal to thereby output a signal of IQ coordinates; and a first noise elimination circuit eliminating a noise in the signal of the IQ coordinates that is output from the demodulation unit, wherein the first noise elimination circuit comprises: a first subtracter subtracting a first noise replica signal from the signal of the IQ coordinates that is output from the demodulation unit; an error information generation unit calculating error information of an output signal of the first subtracter to an ideal signal point of the IQ coordinates; a first frequency detection unit detecting a frequency of the noise based on the error information; and a first amplitude adjusting unit adjusting an amplitude of the first noise replica signal based on the error information and the frequency of the noise detected in the first frequency detection unit to output the first noise replica signal to the first subtracter.