ADAPTIVE DIGITAL FILTER, SIGNAL PROCESSING METHOD, FM RECEIVER, AND PROGRAM

摘要

A complex signal in which one of two signals that are generated from one real signal and that have phases shifted from each other by 90° is a real part and the other signal is an imaginary part is applied as input to an input terminal (301). A filter unit generates an output signal that is a complex signal by means of a convolution operation of this input signal and filter coefficients that are real signals and supplies the result to an output terminal (302). A coefficient control unit composed of a common unit (318) and separate units (319 0 -319 N-1 ) controls the envelope target value based on the input signal and updates the filter coefficients such that the value of the envelope derived from the output signal approaches the envelope target value.