Patent ID: 8126490
Filing Date: 2012-02-28
Classification: H04B,H04L

Abstract:
1. A radio receiver that suppresses multipath noise by imposing operation limitations on amplitude correction for removing amplitude variation responding components of an input signal performed by a demodulator, the radio receiver comprising: an amplitude detecting section for detecting an amplitude level of a signal input to the demodulator; a multipath occurrence state detecting section for monitoring the amplitude level output from the amplitude detecting section, and for detecting a strong multipath occurrence state if an instantaneous drop is small, and detecting a weak multipath occurrence state if the instantaneous drop is large; a multipath occurrence state deciding section for setting an operation limiting level of the amplitude correction in a direction of increase if a degree of the multipath occurrence state detected by the multipath occurrence state detecting section is strong, and setting the operation limiting level of the amplitude correction in a direction of decrease if the degree of the multipath occurrence state is weak; a receiving condition deciding section for deciding receiving conditions of the radio wave according to at least one of a received field level and a modulation signal level; and a limiting level deciding section for making the operation limiting level of the amplitude correction output from the multipath occurrence state deciding section large if a receiving condition decision result output from the receiving condition deciding section is large, and making the operation limiting level of the amplitude correction output from the multipath occurrence state deciding section small if the receiving condition decision result is small.