基于光通信仿真软件的光纤无线电系统研究

发布时间：2018-01-11 14:25

  本文关键词：基于光通信仿真软件的光纤无线电系统研究　出处：《哈尔滨工业大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 光纤无线电技术 外部调制 光外差平衡探测 波分复用

【摘要】：近年来,光纤无线电技术发展非常快,得到了人们广泛的关注与研究。光纤无线电技术利用光纤传输损耗低、容量大的特点,在中心站处,将待传输的基带信号加载到光载波上,通过光纤向基站处传输,达到基站后经过光电转换变为电信号,再经过天线发送给最终用户端。光纤无线电技术是在不远的将来解决最后一公里问题最有前途的方案之一。本文对光纤无线电技术的研究内容如下:简单介绍了直接调制和外部调制的基本原理,并详细的对外部调制的三种调制方式进行了分析与仿真,外部调制可以传输更高速率的信号,马赫-曾德尔调制器是将输入光分成两路信号分别进入调制器的两个光支路,通过控制输入的偏置电压和相位来控制调制方式,并分别比较了在不同光纤传输距离下双边带调制、单边带调制和载波抑制调制的最小误码率。随后,介绍了利用光电二极管的相干特性,利用光程差法产生毫米波的原理,与直接调制/直接检测法相比,通过分析与仿真得出远程光外差法的很多优点。光远程外差法产生的毫米波信号频率非常高,能达到60GHz,本次仿真中就传递频率60GHz的毫米波,在接收端解调得到。介绍了光外差平衡探测技术,经过跟直接探测的链路的增益进行对比发现,光外差探测的链路的增益更高,降低了噪声,提高了链路的信噪比,从而优化链路。由于波分复用技术可以满足如今网络用户数量增加的现状,所以将波分复用技术与光纤无线电技术结合,可以将二者的优势同时发挥出来。先简述了8端口阵列波导光栅的基本原理,分析其输入输出情况,通过仿真得出运用阵列光栅波导的光波分复用技术。最后,研究基于DPSK的千兆无源光网络波分复用,在光线路终端,射频信号被差分相位键控序列产生器调制,并加载到连续激光机产生的频率为193.1THz和193.2THz的光波上,通过光纤链路传输到达解复用器,将耦合的两个光载波分开,研究在不同传输速率和传输距离下,光信号的信噪比和功率的变化。
[Abstract]:In recent years, optical fiber radio technology has developed very quickly, and has been widely concerned and studied. Optical fiber radio technology utilizes the characteristics of low transmission loss and large capacity of optical fiber, and it is located at the central station. The baseband signal to be transmitted is loaded on the optical carrier and transmitted to the base station through optical fiber. After reaching the base station, the signal is converted into an electric signal by photoelectric conversion. Fiber-optic radio technology is one of the most promising solutions to the last kilometer problem in the near future. The basic principles of direct modulation and external modulation are briefly introduced. And the three modulation modes of external modulation are analyzed and simulated in detail. The external modulation can transmit higher rate signal. Mach-Zehnder modulator divides the input light into two optical branches of the modulator and controls the input bias voltage and phase to control the modulation mode. At the same time, the minimum bit error rate of bilateral band modulation, single sideband modulation and carrier suppression modulation under different optical fiber transmission distance is compared respectively. Then, the coherent characteristics of photodiode are introduced. By using the principle of optical path difference method to generate millimeter wave, compared with direct modulation / direct detection method, many advantages of remote optical heterodyne method are obtained by analysis and simulation. The frequency of millimeter wave signal produced by optical remote heterodyne method is very high. In this simulation, the millimeter wave with a frequency of 60GHz is demodulated at the receiver. The technology of optical heterodyne balance detection is introduced. Compared with the gain of the link detected directly, it is found that the gain of the link detected by optical heterodyne detection is higher, which reduces the noise and improves the signal-to-noise ratio of the link. Because wavelength division multiplexing (WDM) technology can satisfy the increasing number of network users, it combines wavelength division multiplexing (WDM) technology with optical fiber radio (fiber-optic radio) technology. The advantages of both can be brought into play at the same time. Firstly, the basic principle of 8-port arrayed waveguide grating is briefly described, and its input and output are analyzed. Finally, the optical wavelength division multiplexing technology using array grating waveguide is obtained by simulation. The wavelength division multiplexing (WDM) of Gigabit passive optical network based on DPSK is studied. At the optical line terminal, RF signal is modulated by differential phase keying sequence generator. It is loaded into the optical waves with the frequencies of 193.1 THz and 193.2 THz generated by the continuous laser, and the two coupled optical carriers are separated by optical fiber link transmission to the demultiplexer. The signal-to-noise ratio (SNR) and power change of optical signals at different transmission rates and distances are studied.
【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】：2016
【分类号】：TN929.1;TN014
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本文编号：1409910