Patent ID: 8194805

Claim:
A digital demodulating apparatus comprising: an intensity changing unit that changes an intensity of a received signal; a channel selecting unit that applies channel selection processing to the signal whose intensity has been changed by the intensity changing unit; a demodulating unit that applies demodulation processing to the signal to which the channel selecting unit has applied channel selection processing; a noise evaluating unit that evaluates an influence of noise components on a desired component in the signal to be input to the demodulating unit; and a gain changing unit that changes, on a basis of a result of the evaluation by the noise evaluating unit, a gain of the change in the intensity of the received signal by the intensity changing unit so that the influence of the noise components is decreased in the signal to be input to the demodulating unit, wherein the gain changing unit comprises an estimating unit that estimates, on the basis of the result of the evaluation by the noise evaluating unit, whether or not changing the gain decreases the influence of the noise components in the signal to be input to the demodulating unit, and the gain changing unit changes the gain when the estimating unit estimates that the change in the gain decreases the influence of the noise components in the signal to be input to the demodulating unit.