發(fā)布時間：2018-01-11 14:25

  本文關鍵詞：基于光通信仿真軟件的光纖無線電系統(tǒng)研究　出處：《哈爾濱工業(yè)大學》2016年碩士論文　論文類型：學位論文

  更多相關文章： 光纖無線電技術 外部調制 光外差平衡探測 波分復用

【摘要】：近年來,光纖無線電技術發(fā)展非�？�,得到了人們廣泛的關注與研究。光纖無線電技術利用光纖傳輸損耗低、容量大的特點,在中心站處,將待傳輸?shù)幕鶐盘柤虞d到光載波上,通過光纖向基站處傳輸,達到基站后經過光電轉換變?yōu)殡娦盘?再經過天線發(fā)送給最終用戶端。光纖無線電技術是在不遠的將來解決最后一公里問題最有前途的方案之一。本文對光纖無線電技術的研究內容如下:簡單介紹了直接調制和外部調制的基本原理,并詳細的對外部調制的三種調制方式進行了分析與仿真,外部調制可以傳輸更高速率的信號,馬赫-曾德爾調制器是將輸入光分成兩路信號分別進入調制器的兩個光支路,通過控制輸入的偏置電壓和相位來控制調制方式,并分別比較了在不同光纖傳輸距離下雙邊帶調制、單邊帶調制和載波抑制調制的最小誤碼率。隨后,介紹了利用光電二極管的相干特性,利用光程差法產生毫米波的原理,與直接調制/直接檢測法相比,通過分析與仿真得出遠程光外差法的很多優(yōu)點。光遠程外差法產生的毫米波信號頻率非常高,能達到60GHz,本次仿真中就傳遞頻率60GHz的毫米波,在接收端解調得到。介紹了光外差平衡探測技術,經過跟直接探測的鏈路的增益進行對比發(fā)現(xiàn),光外差探測的鏈路的增益更高,降低了噪聲,提高了鏈路的信噪比,從而優(yōu)化鏈路。由于波分復用技術可以滿足如今網絡用戶數(shù)量增加的現(xiàn)狀,所以將波分復用技術與光纖無線電技術結合,可以將二者的優(yōu)勢同時發(fā)揮出來。先簡述了8端口陣列波導光柵的基本原理,分析其輸入輸出情況,通過仿真得出運用陣列光柵波導的光波分復用技術。最后,研究基于DPSK的千兆無源光網絡波分復用,在光線路終端,射頻信號被差分相位鍵控序列產生器調制,并加載到連續(xù)激光機產生的頻率為193.1THz和193.2THz的光波上,通過光纖鏈路傳輸?shù)竭_解復用器,將耦合的兩個光載波分開,研究在不同傳輸速率和傳輸距離下,光信號的信噪比和功率的變化。
[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.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN929.1;TN014
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本文編號：1409910