Adaptive matched filter.

摘要

In a modulation system, a demodulator demodulates an intermediate frequency modulated signal and outputs an analog-baseband signal, and an analog-digital converter analog-digital converts this baseband signal. The adaptive matched filter inputs the output of the analog-digital converter and makes symmetrical the impulse response of the propagation path. The decision feedback equalizer inputs the output of the adaptive matched filter and eliminates the intersymbol interference. A reset circuit judges the fading type using tap coefficients within the decision feedback equalizer, and stops the operation of the adaptive matched filter in cases of minimum phase shift type fading. The adaptive matched filter is constructed so as to operate in an intermediate frequency band as well as in a baseband.