AMPLITUDE FLUCTUATION DETECTOR OF DIGITAL POLYPHASE MULTILEVEL CARRIER WAVE SIGNALS

摘要

PURPOSE:To improve characteristics of demodulation system by detecting the fluctuation of input signals from the multiplication output or the amplitude fluctuation of output signal from the discriminator. CONSTITUTION:Judge positive or negative of two detected output signals detected by two locally oscillated signals, judge positive or negative of regenerated output signals of detectors 2 and 8, judge at least one of the regenerated output signals of code discriminators 5 and 6 and differential signals between these discriminator signals and the two detected output signals as well as the positive and negative of differential signal, thus multiplying at least one of the signals of differential of regenerated code discriminators 9 and 10 by multipliers 20 and 21 and detecting the flucturation of input signal or that of amplitude of discriminator output signals by the multiplicated output. This arrangement detects the amplitude fluctuation of input aignal and that of output amplitude of code discriminator without being influenced by the modulation pattern of input signal, thus enabling to obtain remarkable improvement in the characteristics of demodulation system.