DF Relayed OOK and PAM FSO Links with Turbulence and Time Jitter

In recent years, the increasing research and commercial interest for FSO communication systems has included them among the popular and effective communication technologies worldwide. Nevertheless, the main drawback of the terrestrial FSO links is related to the randomly time-varying atmospheric characteristics. In this work, the joint influence of time jitter effect and weak atmospheric turbulence, modeled with the gamma distribution, at the average BER performance of serially relayed Decode-and-Forward terrestrial FSO links, is investigated for two typical modulation schemes, i.e. OOK and PAM. The scope of this work is to extract accurate closed-form mathematical expressions for the system's performance estimation. Furthermore, the corresponding numerical results are presented for various typical FSO parameter values.