Research Of Atmospheric Turbulence Channel Free Space Optical Communication Based On MIMO Equalization

In the field of space optical communication,the key problems focus on the impact and compensate for atmospheric turbulence atmospheric turbulence on the communication performance of the system brought about by the decline and crosstalk.In this thesis,based on multiple overcharged(Multiple-Input Multiple-Output,MIMO)space optical communication technology including MIMO adaptive equalization OMIMO(Optical MIMO)communication system,and applied(Orbital Angular based on orbital angular momentum Momentum,OAM)beam MIMO communication system,the main work and achievements are as follows:1.MIMO channel model was constructed OMIMO Communication System Model based on MIMO equalization algorithm to study the zero-forcing(Zero-Forcing,ZF),Maximum Likelihood(Maximum Likelihood,ML)and MMSE(Minimum Mean Square Error,MMSE)MIMO equalization algorithm works.Based the research of OMIMO communication system based on atmospheric turbulence,the simulation of the influence of the three equalization algorithm for system error rate performance is analyzed;2.Study the atmospheric turbulence channel OAM MIMO system,modified von Karman turbulence atmospheric turbulence spectrum model based on the Monte Carlo method is chosen to establish atmospheric turbulence phase screen,analyze the transmission characteristics of Laguerre-Gaussian Gaussian beam,then study Laguerre-Gaussian beam intensity and phase changes in different turbulence intensity and different transmission distance.3.Study the atmospheric turbulence channel OAM diversity receiving system MIMO adaptive equalization algorithm,Laguerre-Gaussian beams in atmospheric turbulence simulation and OAM MIMO transmission system model,select the CMA(Constant modulus algorithm,CMA)as MIMO adaptive equalization algorithm,and the simulate the influence of the CMA algorithm based on space optical communication system OAM effects of different transmission distances,different intensity of turbulence to reduce the inter-modal OAM crosstalk between different channels.