Error performance of terrestrial FSO links modelled as PPM/Poisson channels in turbulent atmosphere

Considering pulse-position modulation, the error performance of terrestrial free-space optics links modelled as Poisson channels in turbulent atmosphere is assessed. In agreement with recent literature, the impact of scintillations is described by an exponential or lognormal density distribution of the signal counts. Appropriate analytical relationships are developed for uncoded transmission of data. In the sequel, the latter are used to compute the bit error probability at the output of a Reed-Solomon decoder. For comparison reasons, the lower bound, derived from the converse of Shannon´s coding theorem, is also provided