Influence of angle-of-arrival fluctuations on ground-to-satellite laser uplink communication system

A theoretical model was established to describe the influence of the angle of arrival (AOA) fluctuations on the bit error rate (BER) performance of ground-to-satellite laser communication under the Kolmogorov turbulence. A closed form expression of BER of ground-to-satellite laser communication system was then derived based on this model. Then, considering the combined effect of scintillation, beam wander and AOA fluctuations, the probability density function of the received intensity and closed form expressions of BER for an uplink were derived. Coherent detection of circle polarization shift keying modulation was employed, which was suitable for ground-to-satellite laser communication. For an uplink, the BER performance was analyzed and compared to the conditions without taking AOA fluctuations into account under the weak, medium and strong turbulence. Variations in BER as a function of AOA fluctuations were also analyzed. Finally, the influence of intensity scintillation, beam wander and AOA fluctuations on system performance was analyzed based on laser transmission power restrictions. The results show that in addition to the intensity scintillation and beam wander, AOA fluctuations is also a non-negligible factor in the study of communication performance.