PURPOSE: To make the operation of the device stable at a low C/N by using a frequency outputted from a fixed oscillator of a quasi-synchronization detection demodulator for a reference frequency of AFC control and preventing the deterioration in the accuracy of AFC due to a deteriorated C/N ratio.
CONSTITUTION: The controller is made up of a quasi-synchronization detection demodulator 13 converting its intermediate frequency signal into a base band signal demodulating a digital signal, an M multiplier 15 multiplying the frequency of the intermediate frequency by M, a frequency divider 16 frequency- dividing the output signal, a frequency divider 116 frequency-dividing the frequency from the fixed oscillator 14, a phase detector 17 detecting the frequency difference between an output signal of the frequency divider 16 and an output signal of the frequency divider 116, a voltage controlled oscillator 19 whose oscillating frequency is controlled based on the output voltage from the phase detector 17, a comparator 101 comparing error rate information detected by an error detector 100 with a reference value A and a microprocessor 102 controlling an applied voltage to the voltage controlled oscillator 19 based on the result of comparison.
OZEKI HIROAKI
URATA KAZUNAO
KATO HISAYA
