摘要 |
A demodulator for a composite PSK-PSK modulated signal having a 2n-phase main data signal and a 2-phase subdata signal including a frame signal, said demodulator comprising an orthogonal detector 21 producing two orthogonally demodulated signals P, Q, a subdata reproducing section 50 for phase-shifting the orthogonal signals and multiplying together the phase-shifted signals to reproduce the subdata signal, a lock-in phase discriminator 42 for detecting the frame synchronization, and a main data reproducing section 51 for phase-shifting and switching the orthogonal signals in response to the phase discriminator and the reproduced subdata signal to reproduce the main signal.
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