Decision-Directed Slot Synchronization for Pulse-Position-Modulated Optical Signals
نویسندگان
چکیده
In this article, we describe a slot-synchronization algorithm for optical signals transmitted using pulse-position modulation (PPM). This algorithm utilizes PPM symbol decisions in order to generate a slot-timing error signal without the use of guard time around the transmitted laser pulse or synchronization symbols. We derive expressions for the open-loop characteristic curve of the error signal and the closed-loop tracking-error variance of this slot synchronizer for an ideal Poisson photon-counting channel. Simulation results for acquisition as well as tracking under a variety of conditions are presented. Finally, the impact on synchronization performance of implementing the transmitted PPM signal through a repetition code is discussed.
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