Distribution of a synchronization signal in an optical communication system

A receiver arrangement comprising:

• at least one optical detector to receive a combined signal formed by a payload signal amplitude-modulated with a synchronization signal in an optical communication system, the synchronization signal to synchronize network elements in the optical communication system;
• a first reception branch configured to detect the payload signal;
• and
• a second reception branch comprising an amplitude modulation detector to detect the synchronization signal and to obtain a synchronization signal for the receiver arrangement,
• wherein the amplitude modulation detector is to be connected to a phase-locked loop to supply the detected synchronization signal to the phase-locked loop.

A method comprising:

• optically detecting a combined signal formed by a payload signal amplitude-modulated with a synchronization signal in an optical communication system to obtain a detected signal, the synchronization signal to synchronize network elements in the optical communication system;
• detecting said payload signal and said synchronization signal, wherein detecting said synchronization signal comprises performing amplitude demodulation on said detected signal to obtain an amplitude-demodulated signal;
• and
• comparing the amplitude-demodulated signal to a predetermined threshold value.

A method comprising:

• optically detecting a combined signal formed by a payload signal amplitude-modulated with a synchronization signal in an optical communication system to obtain a detected signal, the synchronization signal to synchronize network elements in the optical communication system;
• detecting said payload signal and said synchronization signal, wherein detecting said synchronization signal comprises performing amplitude demodulation on said detected signal to obtain an amplitude-demodulated signal;
• and
• supplying the amplitude-demodulated signal to a phase-locked loop.

A system comprising:

• an optical transmitter unit to accept a payload signal and a synchronization signal that is configured to synchronize network elements in an optical communication system and to output a combined optical transmission signal in which the payload signal is amplitude-modulated by the synchronization signal;
• at least one optical detector to receive the combined optical transmission signal;
• a first reception branch configured to detect the payload signal;
• a second reception branch comprising an amplitude modulation detector to detect the synchronization signal and to obtain a synchronization signal for a receiver;
• and
• a decision-making unit to be connected to the amplitude modulation detector, the decision-making unit to compare the amplitude of the synchronization signal with a predetermined threshold.

A system comprising:

• an optical transmitter unit to accept a payload signal and a synchronizaticn signal that is configured to synchronize network elements in an optical communication system and to output a combined optical transmission signal in which the payload signal is amplitude-modulated by the synchronization signal;
• at least one optical detector to receive the combined optical transmission signal;
• a first reception branch configured to detect the payload signal;
• a second reception branch comprising an amplitude modulation detector to detect the synchronization signal and to obtain a synchronization signal for a receiver,
• wherein the amplitude modulation detector is to be connected to a phase-locked loop to supply the detected synchronization signal to the phase-locked loop.