【作者】 徐智敏；

【导师】 肖沙里；

【作者基本信息】 重庆大学 ， 仪器科学与技术， 2007， 硕士

【摘要】 紫外光通信是一种新型的自由空间光通信方式,它与红外通信相比较具有一些更好的优点,如保密性好、抗干扰性能好,非直视通信,因此,紫外光通信非常适用于军队特种通信对保密的要求。首先对紫外光的传输特性进行了分析,从而选定了波长为256nm的紫外光作为自由空间光通信的载体。这是因为大气层的存在,来自宇宙空间的波长小于290nm的紫外光在到达地表之前就已被吸收干净,近地表面没有来自自然界的干扰。同时紫外光的散射性好,能实现特定区域范围内非视距通信,这与红外和激光通信对双方的方位要求严格,只能用于直线通信大不一样,这也是紫外通信非常吸引人的一个优点。其次,根据紫外通信的特殊性和实际情况分析比较了几种紫外光的调制方式,选择了光源以及一种适合紫外光调制的方案。本文的紫外通信系统采用特殊的紫外光调制方式,这是由紫外通信在光源选择上的局限性决定的,对于256nm这个波段上的紫外光,无论是紫外激光还是紫外LED都具有无法克服的缺点,通信系统选用了紫外气体发电灯作为光源,从而决定了所采用的紫外光调制方式,这对于整个系统的硬件设计的实现具有重要意义。第三,结合紫外通信硬件系统的传输速率,为实现以紫外光为媒介的语音对话,提出了一种语音编码压缩的方案。采用TI公司的C6711DSK作为编码压缩的硬件平台,给出了主机P87C51、AMBE2000以及片外AD转换芯片的关系。本设计的目的是结合现阶段技术条件,对用于军队的紫外光语音通信的进行了初步的探索。通过三年来的研究工作,已经在光的调制和语音编码上积累了一定经验,实现了低速率下的紫外光通信。初步实验表明该方案切实可行,值得继续做进一步的研究。更多还原

【Abstract】 Ultraviolet Optics Speech Communication is a new type of communication system in free space optics communication fields. Its excellent performances such as safety,anti-interference, Non Line-of-Sight, make it different from infrared optics communication. Hence, ultraviolet optics communication gratifies the need of special and confidential communication in army.Firstly, according to analysis of ultraviolet optics transmitting characteristics, we choose ultraviolet light with wavelength of 256nm as the carrier of free space optics communication. Because of aerosphere, the astrospace ultraviolet light whose wavelength is less than 290nm is absorded before it reaches the earth’s surface. There is not exist disturbance which comes from the nature. Furthermore, ultraviolet optics can realize non line-of-sight communication in certain area because of its dispersion. That is much different from the rigorous orientation’s restrictions of transmitter and receiver in the infrared optics and laser communication which is only used in line-of-sight communication. This is a very fascinating characteristic of ultraviolet optics communication.Secondly, according to particularity and the real conditions, analysed and compared several modulating methods, ultimately we choose the ultraviolet lamp and one adaptive modulating method. Because of the restrictions in the choice of ultraviolet optics lamp, our ultraviolet optics communication system adopts special ultraviolet optics modulating method. For the 256nm-ultraviolet-optics, either ultraviolet laser or ultraviolet led has some disadvantages which make them not be used in ultraviolet optics communication. The system choose the ultraviolet gas discharge lamp as lamp-source, Then the modulating method is decided, this is significant for the hardware design of the whole system.Thirdly, considering transfers velocity of ultraviolet optics communication system, we design a speech encoding method in order to realize speech communication through the ultraviolet optics. Using C6711DSK of TI as the speech encoding plantform, the relationship of host p87c51, AMBE2000 and off-chip TLC320AD535 is given.The purpose of the design is to utilize the current technology and condition that we hold to do some elementary research on ultraviolet optics speech communication used in army. For three years hard research works, we accumulate some experiences in modulating of ultraviolet optics and speech encoding. We complete the ultraviolet optics communication in low velocity. The results of experiment indicate our design is feasible and worthy of further research.更多还原