Ethernet Optimization Model Research And System Validation For Space Optical Communication

Atmospheric laser communications with high communication speed,anti-electromagnetic interference ability,confidentiality,easy to move,occupy a small architectural resources,low operating costs and so on.It can be used in special occasions that require confidential communications,such as nuclear power plants,prisons,border guards,government agencies,airports and other government departments.At the same time,atmospheric laser communication overcomes the shortcomings of narrow bandwidth and low speed of copper in-house,and is the preferred solution for broadband access in the “last mile”.It can also provide more communication modes for telecom operators.It is the main measures to achieve the leapfrog development of China's information technology.Incomplete data will be directly discarded in traditional Ethernet interface technology.And atmospheric laser communication system is a time-varying system due to turbulence and other factors.So it is likely to cause data loss when access to the Ethernet.At the same time,TCP will start the congestion control mechanism due to the loss of the message,thus reducing the communication performance.This thesis intends to explore an Ethernet communication optimization model that can adaptively control the size of the TCP segment at the e Ethernet receiver.This model plays an important role in the development and application of space optical communication.This article is divided into the following three parts:The first part: Explore the channel environment factors that have an important impact on laser transmission,and focus on the influence of atmospheric turbulence on laser transmission,including the formation of turbulence and the effect of atmospheric turbulence on laser transmission;The effects of atmospheric turbulence on the sunlight modulation under different channel conditions are experimentally studied through the sun arrival angle fluctuation measurement experiment,which indirectly reflect the modulation effect of atmospheric turbulence on laser transmission.Finally,the effect of atmospheric turbulence on Ethernet communication is analyzed,and it provide a theoretical basis for the optimal model of subsequent adaptive Ethernet communication.The second part: Designing the corresponding space optical communication equipment for the adaptive Ethernet communication optimization model.Firstly,explored an image processing algorithm that the optical communication equipment can reflect the modulation effect of atmospheric turbulence on the laser transmission according to the fluctuation of the light spot.Secondly,in order to optimize the model of laser communication transmission and reduce the probability of communication interruption,this paper designs the space division multiplexing mechanism jointly transmitted by beacon and communication light.Finally,design each subsystem according to system requirements.The third part: Set up a platform for field communication experiment environment and carry out field communication test to test the adaptability of laser communication equipment to the atmosphere.Do laser communication experimentsts with optimized control algorithm and no optimized control algorithm,and measure the real-time transmission of information of the laser communication with haze,snow,sunny and other meteorological conditions.The experimental test results are analyzed and summarized to further verify the feasibility of optimizing the model.In order to suppress the influence of atmospheric turbulence on laser transmission,a series of technical means such as adaptive optics,large aperture receiving technology,multi-beam emission technology,and error control coding technology have been proposed.Compared with multi-beam emission technology,adaptive optics technology,large aperture or synthetic aperture receiving technology,error control coding technology and other atmospheric channel suppression technologies,this paper explores a model that can suppress the influence of atmospheric channels on wireless laser communications,in the hope of providing support for the research of spatial optical communication technologies.