【作者】 刘瑞雄；

【导师】 张涛；

【作者基本信息】 海南大学 ， 通信与信息系统， 2010， 硕士

【摘要】 大气光通信是无线通信领域的一个研究热点,它是一种以大气为传输媒质,通过激光或光脉冲传送数据的通信系统,又称为“无线激光通信”,享有“虚拟光纤”的美誉。大气光通信结合了微波通信和光纤通信的优点,具有传输容量大、建网速度快、无须授权、保密性好等特点。在大气光通信系统中,由于在传输过程中受气大气吸收、散射、湍流等众多因素的影响,造成了光能量的衰减、光强闪烁等现象,能否解决这些影响是大气激光通信推广应用的关键,因此,对大气光通信信道的研究就显得格外重要。本文首先系统叙述分析了大气衰减及湍流效应对激光传输的影响,以及对应的光信号的发射与接收,并详细分析了各种因素对误码率的影响。接着在此基础上结合通信理论给出信道模型,结合南海海域的大气特性进行仿真,以图形来观察激光传输受到大气影响、空间损耗等外界环境的作用后,激光能量的变化及分布情况。通过深入分析各种外在因素对大气光通信系统的影响,提出几种抑制大气信道影响的方法,为进一步研制出高性能的通信系统打好理论基础。本文的研究对大气无线光通信系统的设计具有重要的指导意义和参考价值。更多还原

【Abstract】 Atmospheric laser communication has been a research focus in the field of wireless communication, it is a digital communication system transmitted by laser or optical plus in the atmosphere. It is also called "Wireless Optical Communication" and enjoys a good reputation with "virtual fiber". Atmospheric laser communication both has microware and laser communication’s advantages. Further more. it is structured with some inimitable characters such as unlimited bandwidth, no frequency admission, low cost, strong anti-jamming, good transmission secrecy, ease and speed of deployment and so on. Because such a lot of factors as atmospheric scattering, refracting, turbulence, etc. in the course of transmitting in the atmospheric laser communication system will cause the energy of laser to decay, strength of laser to fluctuate, the random deflection of the light beam, it is a key to overcome the influence. So the study on atmospheric laser communication channel seems extremely important.This paper has narrated and analyzed the effect of atmospheric random channel to wireless laser communication and light transmit and receive correspond to wireless optical communication, in addition we detailed analysis of various factors on the bit error rate(BER). Then the paper provide the channel model based on it and communication theory, and combined with the South China Sea to simulate the atmospheric properties. On the basis of these figures, we can observe the change and distribution of laser energy goes through affected by atmospheric, space loss, and other external environment with all kinds of figure. Through in-depth analyzed of various external factors on the atmospheric optical communication systems. We brought forward a few of methods to reduce influence of air boundary layer for the further development of high performance communication system to lay a good theoretical basis.更多还原