水下光通信OOK调制解调系统研究

发布时间：2018-12-09 21:36

【摘要】：水下无线通信对人类开发和利用海洋资源十分关键，无论商业还是军事方面，水下无线通信都发挥着极其重要的作用。目前的水下无线通信方式大体分为三类：水下长波无线电通信（主要用于军事上）、水下无线声通信与水下无线光通信。相比于其它两种通信方式，水下无线光通信具有以下优势。首先，通信速率高，光波在水下的通信速率可达Gbps量级；其次，带宽高，光波频率高，使其承载能力强；第三，保密安全性高，光通信具有较强的抗电磁波与核辐射干扰能力，且激光光束具有很好的方向性，如被拦截，接收方会迅速发现中断事故；最后，具有体积小、功耗低和价格相对便宜等优点。本文基于对水下光通信OOK调制解调系统的研究，完成工作如下：（1）介绍目前水下无线通信的三种主要方式及其优缺点，并阐述了水下无线光通信技术的国内外发展现状及发展趋势。（2）分析研究海水的光学特性。针对海水的组成成分，分析其对可见光的吸收和散射，依此建立海水信道通信链路模型和修正光的水下衰减公式，并根据不同海水类型计算不同波段光波的传输距离。（3）对OOK、LPPM和DPIM三种调制方式进行分析介绍和性能对比，并选择OOK调制作为系统调制方式。（4）阐述了水下无线光通信的基本原理，实现了对发射光源、光探测器的选型和对调制/解调电路模块、信号处理电路模块、系统软件和防水装置的设计，并完成了对整个系统的组装。（5）通过实验室水箱实验验证了系统的可行性，并利用所设计水下无线光通信系统实现了威海近海岸浑浊水域（漫衰减系数约为0.5152m-1），，在接收模块输入阻抗为34kΩ，通信速率为9600bps时，最大传输距离达24m（20m内可实现无差错通信）与接收模块输入阻抗为70kΩ，通讯速率为4800bps时，最大传输距离达27m，误码率在4103以内的水下无线光通信。
[Abstract]:Underwater wireless communication plays a very important role in the development and utilization of marine resources. At present, underwater wireless communication is divided into three types: underwater long wave radio communication (mainly used in military), underwater wireless acoustic communication and underwater wireless optical communication. Compared with the other two communication modes, underwater wireless optical communication has the following advantages. First, the communication rate is high, the communication rate of light wave can reach Gbps order of magnitude, secondly, the high bandwidth and the high frequency of light wave make the carrying capacity of light wave strong. Third, the security is high, the optical communication has strong ability to resist the interference of electromagnetic wave and nuclear radiation, and the laser beam has good directionality, if intercepted, the receiver will find the interruption accident quickly. Finally, it has the advantages of small size, low power consumption and relatively cheap price. Based on the research of underwater optical communication OOK modulation and demodulation system, the work of this paper is as follows: (1) introduce the three main ways of underwater wireless communication and their advantages and disadvantages. The present situation and development trend of underwater wireless optical communication technology at home and abroad are also described. (2) the optical properties of seawater are studied. According to the composition of seawater, the absorption and scattering of visible light are analyzed, and the communication link model of seawater channel and the underwater attenuation formula of modified light are established, and the transmission distance of light waves in different bands is calculated according to different sea water types. (3) three modulation modes, OOK,LPPM and DPIM, are analyzed and compared, and OOK modulation is chosen as the modulation mode. (4) the basic principle of underwater wireless optical communication is expounded, and the design of emitting light source, type selection of photodetector, modulation / demodulation circuit module, signal processing circuit module, system software and waterproof device are realized. And completed the whole system assembly. (5) the feasibility of the system is verified by laboratory water tank experiment, and the muddy area near the coast of Weihai (diffuse attenuation coefficient is about 0.5152m-1) is realized by using the designed underwater wireless optical communication system. The input impedance of the receiving module is 34k 惟. When the communication rate is 9600bps, the maximum transmission distance is 24m (error-free communication within 20m) and the input impedance of the receiving module is 70k 惟. When the communication rate is 4800bps, the maximum transmission distance is 27m, and the BER is less than 4103.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.3

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