The Effects On FSO System Links Turbulence Channel With Pointing Errors

With the development of society people demand for communication quality speed and capacity also increased free space optical communication(FSO)because of its large capacity small colume strong anti-interference ability and many other advantages more and more attention,has become a hot spot for international research in the world,and with the rapid development of aviation in recent years,research on FSO system becomes more and more urgent.The main channel of FSO is the atmospheric channel,so the atmospheric turbulence is one of the important reasons affecting the quality of communication.The influence of the pointing errors can not be ignored so it is having great theoretical significance and practical value to study the effect on FSO system links over atmospheric turbulence channel with pointing errors.The research contents of this paper are as follows:(1).Summarizesthe advantage of the FSO and the research significance,finishing the FSO development and the present stage domestic and foreign research dynamic and developing trend.In this paper,the significance of the effects of FSO links over atmospheric turbulence with pointing errors and the research trends are introduced.At the same time,the theoretical basis of atmospheric composition and turbulence effect are introduced,and also describing the pointing errors theory in detail.(2).Several channel models of the probability density are given.Introducing the modulation of several communication system and giving each modulation system transmission,solt error and packet error expressions.(3).The effect of atmospheric turbulence on the performance of FSO system is studied.The MeijerG function is used to establish the theoretical model of the error rate,outage probability and channal capacity of the OOK direct detection system,and the simulation results are analyzed by using Matlab.The theoretical model of the bit error rate and channal capacity coherent detection system is established.Compared with the above system,the optimal system design method is given.(4).The performance of FSO links over atmospheric turbulence with pointing errors is studied and giving the expression of the probability density function.Using MeijerG function to establish the theoretical model of OOK direct detection system under combined effects of bit error rate,outage probability and channel capacity.UsingMatlab simulation analysis,and the impact system performance is summarized.(5).The theoretical model of the coherent detection system and the PoLSK direct detection system under the combined effects of bit error and channel capacity.The three systems are compated and analyzed and giving the best way.(6).The effect of OOK direct detection system under the atmospheric turbulence and the combined effect are compared their bit error rate and channel capacity.Get under the combined effects of bit error rate is higher,and channel capacity will decrease.It shows that the influence of the pointing error can not be ignored,and the combined effects is closer to the actual.