Analysis of Beam Wander and Scintillation in Ground-to-Satellite FSO system with DPSK

Turbulence and beam wandering are major factors that affect the performance of a laser beam traveling from a ground-to-satellite (uplink). In this paper the performance of the optical uplink with differential phase shift keying (DPSK) scheme is evaluated in order to determine the optimum beam size that minimizes the average bit error rate (BER) and outage probability. Considering the combined effect of turbulence, and beam wandering close-form expressions for BER and outage probability are derived. The accuracy of the derived close-form expressions are verified by applying appropriate simulation scenarios, and numerical results. The obtained results show that the optimum beam size is 2 with zenith angle changes from 0 to 35°. This paper also, studies the system performance on optimized beam size considering the effect of changing satellite altitude, transmit power and zenith angle.