Carrier reproducing circuit

Abstract

A carrier reproducing circuit capable of judging the polarity of alienation frequency. A TMCC section is detected from the synchronous detection output from a synchronous detection circuit () by a TMCC section detecting circuit (), the synchronous detection output is converted to a signal point arrangement by a signal point arrangement converting circuit (), the phase of the converted signal point position signal is rotated at a predetermined angular velocity for each symbol of the TMCC by a phase rotating circuit (), the signal position signal whose phase is rotated is phase-detected by a phase detector (), an auto-correlation function of the phase detection output in the TMCC section is determined by an auto-correlation function determining circuit () and angular velocity information based on the period of the waveform of the determined auto-correlation function is obtained, the phase-rotation angular velocity at the phase rotation circuit () is subtracted from the obtained angular velocity by a subtracting circuit (), and sine and cosine wave data on frequency based on the output of the subtraction are generated and sent to the phase detection circuit () by a numerical control oscillator ().