DIGITAL DEMODULATING CIRCUIT, MAXIMUM DETECTING CIRCUIT, AND RECEPTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide the digital demodulating circuit which can operate fast and meet its size reduction and IC-implementation and has a synchronous detecting circuit of high practicability. SOLUTION: A phase comparator 10 generates a momentary phase signal of an input modulated signal with a carry signal from a carry generator 11. A frequency difference detector 13 is supplied with the momentary phase signal in a preamble pattern period through a phase memory circuit 12 after a reproduced clock signal becomes stable, and generates a frequency difference correction signal according to the signal in this period and supplies it to an adder 14 to correct the frequency difference. A phase shift quantity detector 16 after obtaining the phase difference from a reference phase of each symbol generates a histogram, determines the phase difference of the highest frequency as the phase difference from the reference phase of each symbol, and generates and supplies a phase difference correction signal to an adder 17 to remove the phase difference. Data are reproduced from the signal after this removal.