| 摘要 |
PURPOSE:To obtain a demodulator for preventing the degradation of the equalization characteristics of a decision feedback type equalizer by preventing step- out regardless of the presence/absence of fading relating to the demodulator provided with the decision feedback type equalizer suitable when it is used in a digital radio communication system. CONSTITUTION:A phase comparator 17 compares the phases of the output clock frequency signals of a variable amplifier 31 and the output signals of a VCO 18, outputs an error voltage corresponding to the phase difference and variably controls the output signals of the VCO 18. The output signals of the VCO 18 are inputted to A/D converters 13 and 14 as sampling timing clocks and the decision feedback type equalizer 19 outputs data for which intra-code interference 15 removed. A controller 32 monitors the tap weighing coefficient of the decision feedback type equalizer 19 and controls the amplification degree of the variable amplifier 31 so as to the input voltage of the phase comparator 17 is a prescribed value at all times corresponding to the monitored value. |
