FRAME SYNCHRONIZING SIGNAL DETECTOR AND CARRIER REPRODUCING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a frame synchronizing signal detector capable of exactly detecting a frame synchronizing signal even when offset occurs in a carrier frequency. SOLUTION: This device is provided with plural multilevel means 31a-31e for making the inter-symbol difference of demodulated signals I1 and Q1 formed by demodulating an input signal, to which phase modulation is applied, into multilevel with respectively mutually different thresholds, plural correlative means 31f-31h for respectively counting correlation between these respective multilevel signals and a signal ΔUW showing the preset inter-symbol difference of the frame synchronizing signal and detecting means 31i-31l for detecting any one of these respective count values practically exceeds a preset reference value α.