到达角起伏对上行星地激光通信系统性能的影响

在Kolmogorov湍流模型下，建立了到达角起伏对星地激光通信误码性能影响的理论模型。基于该模型，推导了星地激光通信系统误码率的闭合表达式。综合考虑光强闪烁、光束漂移和到达角起伏，推导出三者共同作用下，星地系统上行链路的接收光强概率密度解析式以及误码率的闭合表达式。文中采用的调试方式是适合星地激光通信的相干探测圆偏振调制。针对上行链路，仿真分析了弱、中、强湍流下，三者共同作用时，星地激光通信系统的误码率，并与不考虑到达角起伏条件下进行了比较。还分析了到达角起伏与误码率的变化关系，以及在考虑发射功率受限的条件下，三者共同作用对系统性能的影响。研究结果表明，除了光强闪烁和光束漂移以外，到达角起伏也是通信性能中不可或缺的因素。

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.