New time diversity structure used in free space optics links with a tracking system

This paper proposed a new time diversity structure using over free-space optics (FSO) links with a tracking system. A dual-diversity scheme with beam tracking introduces a power-fading model for an FSO system utilizing beam tracking through atmospheric turbulence. Further, the paper derives a closed-form bit error rate (BER) for time-diversity scheme, taking into account the tracking error, coherence of the diversity signals and photo detector noise. It is shown that time diversity is a clever mitigation technique for improving transmission reliability for the FSO system with beam tracking.