Spectral modelling of an optical PPM satellite link for timing extraction

Optical pulse position modulation is highly suited for deployment over the satellite channel due to its high sensitivity and desirable low duty cycle for the laser. The format synchronisation requirements are yet to be considered specially on the frame level. The authors present an original technique that can be used to extract the frame phase directly from the incoming data stream. Natural sequences are identified and original Min synchronisers are implemented and used to identify the frame frequency and phase. The method does not entail redundancies or complex implementations. Tracking of two additional Min sequences is demonstrated to be beneficial resulting in a timing variance reduction from 12 to 3.6×10^-3 rad ²