ANTI PHASE-AMBIGUITY FOR PHASE-SHIFT KEYING BINARY TRANSMISSION SYSTEMS

摘要

A circuit arrangement to eliminate the phase ambiguity at a receive terminal in phase-shift keying binary transmission systems. The received PSK binary signal is simultaneously applied to a conventional synchronous demodulator and a so-called non-ambiguous demodulator which may be in analog or digital form. The outputs from both demodulators are compared to provide a signal having a first state when both demodulator outputs are in phase and having a second state when said demodulator outputs are in phase opposition. Logic means are provided to detect the state of the comparison signal in order to control inverter means adapted to reverse the demodulated original message from the synchronous demodulator when said comparison signal is in its second state.