Research On The Influence Of Kolmogorov And Non-kolmogorov Turbulence In Uplink Ground-to-satellite Laser Communication

For ground-to-satellite laser communication,the atmosphere is part of the communication channel,and the optical signal is affected by the atmospheric turbulence in the process of transmission.According to the actual situation of atmospheric turbulence in the satellite to ground laser communication,the effects of the Kolmogorov turbulence of the troposphere and the non-Kolmogorov turbulence of the stratosphere on the performance of uplink ground-to-satellite laser communication are studied,respectively.Firstly,in the stratosphere,the non-Kolmogorov turbulence model closer to the actual situation is used to research the satellite laser communication system rather than the kolmogorov turbulence model,which is adopted in the previous studies.It provides a closer theoretical basis for the performance analysis of the satellite laser link.Secondly,in the troposphere and the stratosphere,the effect of AOA fluctuation on the laser performance of the satellite is proposed for the first time,and the closed expression of the system error under the influence of AOA fluctuation is deduced.At the same time,the influence of intensity scintillation,beam wander and AOA fluctuation on the bit error rate of the uplink is studied on the basis of the common influence of intensity scintillation and beam wander.This research is more in line with the actual situation of atmospheric turbulence on the communication performance influence.For the uplink,the bit error rate of the ground-to-satellite laser communication system is analyzed emphatically and compared with that without considering the AOA fluctuation condition.Besides,in the case of the laser emission power restriction,to meet the requirements of basic ground-to-satellite laser communication,the influence of three factors on BER in uplink is analyzed.Finally,Minimum Shift Keying(MSK)modulation with coherent detection is introduced into the satellite-to-ground laser communication system,and the combination of the inherent noise of uplink such as intensity scintillation and beam wander are considered,the communication performance of MSK modulation system of coherent detection in the uplink is researched.Using the Gamma-Gamma channel model to describe the turbulent intensity of weak,medium and strong turbulence,theclosed forms of bit error rate(BER)of MSK modulation system in the uplink are derived.Moreover,in order to select the optimal system parameters and configuration and optimize the MSK system to achieve good communication performance,the influence of the transmitter and receiver parameters on the MSK system such as the divergence angle,the zenith angle,the transmitter beam radius and the receiver diameter are also studied.This research provides a good choice of the good performance,low system complexity and simple modulation mode for the satellite-to-ground laser communication system.