OFDM SYNCHRONIZATION DEMODULATION CIRCUIT

摘要

The invention provides an OFDM synchronization demodulation circuit which includes a receiving circuit for receiving an orthogonal frequency division multiplex (OFDM) modulation signal, an orthogonal detection circuit for orthogonally detecting the OFDM modulation signal from the receiving circuit by using a restored carrier, a demodulation circuit for orthogonally demodulating the detected OFDM multiplex modulation signal from the orthogonal detection circuit through a sampling of the OFDM multiplex detection signal by using a restored clock, a constellation analyzing circuit for analyzing the constellation of demodulated symbols of predetermined carriers in the demodulated OFDM multiplex signal signal, a carrier frequency deviation detection circuit for detecting a frequency deviation of the restored carrier based on a rotation of the constellation of the demodulated symbol detected by the constellation analyzing circuit, a carrier restoration circuit responsive to the frequency deviation detected by the carrier frequency deviation detection circuit for controlling the restored carrier, a clock frequency deviation detection circuit for detecting a frequency deviation of the restored clock based on rotations of the constellations of at least two demodulated symbols detected by the constellation analyzing circui, and a clock restoration circuit responsive to the frequency deviation detected by the clock frequency deviation detection circuit for controlling the restored clock.