光载毫米波信号产生及光纤传输特性评估

发布时间：2018-03-13 15:24

本文选题：光载射频　切入点：光载毫米波信号　出处：《中南民族大学》2014年硕士论文　论文类型：学位论文

【摘要】：光载射频通信（Radio-over-Fiber，ROF）充分结合光纤通信和射频通信，使用光纤链路作为射频信号的传输介质，充分利用光纤通信容量大、损耗低、能有效抵抗电磁干扰等特性和射频通信的灵活高效等优势，能有效解决未来宽带无线通信中带宽、容量和传输距离的需求。光载毫米波信号产生方法是实现ROF通信的关键技术之一。本论文以光载毫米波信号的产生方法和传输特性为主线展开研究，主要包括两个方面的工作：一是分析总结现有光载毫米波信号产生方法，二是提出改进型光载毫米波信号产生方法。第一方面包括：1）介绍了直接调制、外部调制、光学外差调制等方法，理论推导了外部调制产生光载毫米波信号的频谱结构；2）阐述了如何调整调制器偏置和本振信号产生双边带(DSB)、单边带(SSB)和光载波抑制(OCS)双边带三种制式的光载毫米波信号，并在Optisystem7.0软件中对这三种光载毫米波信号的传输特性进行了分析评估，结果表明在光纤中传输时，DSB制式的光载毫米波信号存在功率起伏衰落效应，SSB和OCS制式的光载毫米波信号存在码元缩窄效应。第二方面针对外部调制技术提出改进方案。改进思路是：先用本振信号调制连续光激光器出射的光波，，产生SSB或者OCS制式的光载毫米波信号,然后将基带信号加载到光载毫米波信号的一个频率成分上。这种光载毫米波信号可以消除功率起伏衰落效应和码元缩窄效应。论文详细阐述了两种改进的外部调制方案——改进的SSB制式光载毫米波信号的产生和改进的OCS制式光载毫米波信号的产生，对两种方案进行了理论分析和模拟仿真。结果表明，与改进之前相比，在同等条件下，改进方案所产生的光载毫米波信号通过光纤传输时能有效抑制光纤色散的影响，无码元缩窄效应，改善了系统误码性能。
[Abstract]:Optical radio frequency communication radio-over-Fiberro) fully combines optical fiber communication with radio frequency communication, uses optical fiber link as the transmission medium of radio frequency signal, and makes full use of optical fiber communication with large capacity and low loss. It can effectively resist the characteristics of electromagnetic interference and the advantages of flexible and efficient radio frequency communication, and can effectively solve the bandwidth in future broadband wireless communication. The requirement of capacity and transmission distance. The generation method of light-borne millimeter-wave signal is one of the key technologies to realize ROF communication. In this paper, the generation method and transmission characteristics of light-borne millimeter-wave signal are studied. It mainly includes two aspects: one is to analyze and summarize the existing methods of millimeter-wave signal generation, the other is to propose an improved method of millimeter-wave signal generation. The first aspect includes the introduction of direct modulation, external modulation, optical heterodyne modulation, etc. In this paper, the spectrum structure of the optical millimeter-wave signal generated by external modulation is derived theoretically.) how to adjust the modulator bias and the local oscillator signal to produce the two-sided band DSBs, single sideband SSBs) and the optical carrier suppression (OCS) two-sided band three optical millimeter-wave signals are discussed. The transmission characteristics of the three kinds of light-borne millimeter-wave signals are analyzed and evaluated in Optisystem7.0 software. The results show that the power fluctuation and fading effect exist in the optical millimeter-wave signals of the DSB system and the optical millimeter-wave signals in the OCS system have the symbol narrowing effect when they are transmitted in the optical fiber. In the second aspect, an improved scheme is put forward for external modulation technology. The idea of improvement is that the local oscillator signal is first used to modulate the light wave emitted by the continuous optical laser to produce the SSB or OCS optical millimeter wave signal. Then, the baseband signal is loaded into a frequency component of the light-loaded millimeter-wave signal, which can eliminate the power fluctuation fading effect and the symbol narrowing effect. Two improved external modulations are described in detail. The generation of improved SSB optical millimeter wave signal and improved OCS optical millimeter wave signal, The theoretical analysis and simulation results of the two schemes show that under the same conditions, the optical millimeter wave signal generated by the improved scheme can effectively suppress the influence of fiber dispersion when the optical millimeter wave signal is transmitted through the fiber. The error performance of the system is improved without symbol narrowing effect.
【学位授予单位】：中南民族大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

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