中红外无线光通信的研究

发布时间：2018-08-23 20:02

【摘要】：近年来随着骨干网的建成以及最后一公里问题的出现,自由空间光通信技术以其较高的通信速率与安全性能等优点引起了人们的重视。随着大功率半导体激光器技术的成熟以及量子级联激光器的进步,解决了中红外激光光源的问题,中红外无线光通信以其更低的大气信道影响,更小的通信损耗,以及更远的通信距离和更高的通信稳定性,在一定程度上突破了近红外无线光通信技术在大气信道中的局限性,成为有望取代近红外无线光通信的一种十分有前途的无线光通信方式。本文对基于PPM调制的中红外无线光通信系统进行了研究。首先,对无线光通信的大气信道中各种影响因子进行了理论分析,在此基础上利用Matlab搭建无线光通信系统模型,分析了基于PPM调制的中红外无线光通信系统相对于近红外无线光通信系统在不同的大气信道影响因子下具有更高的通信可靠性,对中红外与近红外在通信性能上进行对比分析。此外,基于所选器件的特性,对高斯模型下的光束对准情况进行了建模与仿真分析,进而对中红外无线光通信的通信性能做进一步的分析。接着,根据中红外光源与光电探测器的性能,设计了基于FPGA的中红外无线光通信系统的发射端与接收端电路,并对电路进行调试。发射端利用FPGA控制中红外无线光源发射信号,接收端通过放大、滤波以及比较电路,将接收到的信号经处理后传送给FPGA进行进一步分析。同时,根据中红外光源对于信号的要求进行了基于FPGA的PPM调制与解调程序的设计,搭建通信系统,对整个通信系统进行调试与实验,实现了基于PPM调制的以中红外激光作为载波的无线光通信。
[Abstract]:In recent years, with the construction of backbone network and the emergence of the last kilometer problem, free space optical communication technology has attracted people's attention because of its high communication rate and security performance. With the development of high power semiconductor laser technology and quantum cascade laser, the problem of medium infrared laser source has been solved. The medium infrared wireless optical communication has lower atmospheric channel influence and smaller communication loss. As well as longer communication distance and higher communication stability, it breaks through the limitation of near infrared wireless optical communication technology in atmospheric channel to some extent. It is expected to replace near infrared wireless optical communication as a promising wireless optical communication mode. In this paper, the medium-infrared wireless optical communication system based on PPM modulation is studied. Firstly, the influence factors of wireless optical communication in atmospheric channel are analyzed theoretically, and then the model of wireless optical communication system is built by using Matlab. Compared with the near infrared wireless optical communication system, the medium infrared wireless optical communication system based on PPM modulation has higher communication reliability than that of the near infrared wireless optical communication system under different influence factors of atmospheric channel. The communication performance of the middle infrared and near infrared communication systems is compared and analyzed. In addition, based on the characteristics of the selected devices, the beam alignment under Gao Si model is modeled and simulated, and the communication performance of mid-infrared wireless optical communication is further analyzed. Then, according to the performance of the mid-infrared light source and photodetector, the transmitter and receiver circuits of the mid-infrared wireless optical communication system based on FPGA are designed, and the circuits are debugged. The transmitter transmits the signal by using the mid-infrared wireless light source controlled by FPGA, and the receiver transmits the received signal to the FPGA for further analysis by amplifying, filtering and comparing circuit. At the same time, according to the signal requirement of the mid-infrared light source, the program of PPM modulation and demodulation based on FPGA is designed, the communication system is built, and the whole communication system is debugged and tested. The wireless optical communication based on PPM modulation is realized, in which the medium infrared laser is used as carrier.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

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