FM Demodulator with Extended Kalman Filter

摘要

The present invention relates to a demodulation apparatus for demodulating a received signal having an interference signal. The object of the present invention is to robust FM demodulation even when the communication environment is jammed by using an improved extended Kalman filter in an FM communication system in which a co-channel phenomenon occurs randomly. The constitution thereof includes storage means, observation value judgment means, state estimation means and error calculation means. The memory means stores the scale factors and provides the scale factors according to the situation. The observation value discrimination means receives the reception signal and the error calculation result, analyzes the reliability of the reception signal by referring to the scale factor from the storage means, identifies whether or not the interference signal is included in the reception signal, and corrects the reception signal. The state estimating means receives the corrected observation value from the observation value judging means and predicts the state, and outputs the state estimation calculation by receiving the error calculation result. The error calculation means receives the predicted state value from the state prediction means, calculates the error, and outputs the error calculation result to the observation value determination means and the state estimation means.