本文選題：光正交頻分復用　切入點：發(fā)射端　出處：《電子科技大學》2014年碩士論文

【摘要】：隨著網(wǎng)絡傳輸容量需求的不斷增加,對于光通信網(wǎng)絡的傳輸要求也越來越高,同時數(shù)字信號處理技術與集成電路的不斷發(fā)展使得正交頻分復用(OFDM)技術越來越得到人們的關注,將正交頻分復用技術引入光通信是近年來的研究熱點。光正交頻分復用技術結(jié)合了正交頻分復用和光纖通信技術的優(yōu)點可以構(gòu)造出高頻譜利用率、大容量、低成本的傳輸網(wǎng)絡。光正交頻分復用系統(tǒng)可以分為直接檢測光正交頻分復用系統(tǒng)(DD-OFDM)與相干檢測光正交頻分復用系統(tǒng)(CO-OFDM),同時光正交頻分復用可以與波分復用技術相結(jié)合構(gòu)造出容量更大的傳輸系統(tǒng)。由于光正交頻分復用系統(tǒng)具有優(yōu)越的性能使得光正交頻分復用系統(tǒng)技術在長途通信、光接入網(wǎng)等應用中具有很大的潛力,但是系統(tǒng)所使用的調(diào)制器與發(fā)端調(diào)制結(jié)構(gòu)直接影響著系統(tǒng)的性能。本論文正是針對上述問題,分析了調(diào)制器的調(diào)制特性與發(fā)端調(diào)制結(jié)構(gòu)對系統(tǒng)性能的影響,并依據(jù)各個系統(tǒng)應用的場景對其進行結(jié)構(gòu)上的優(yōu)化。本論文主要內(nèi)容如下:1.介紹了OFDM技術的基本原理,并歸納總結(jié)了常見光OFDM系統(tǒng)的實現(xiàn)方法以及特點。2.研究了DD-OFDM系統(tǒng)中MZM調(diào)制非線性的影響和利用光I/Q調(diào)制結(jié)構(gòu)優(yōu)化了基帶單邊帶調(diào)制。首先介紹了DD-OFDM系統(tǒng)典型結(jié)構(gòu)并搭建了單邊帶DD-OFDM仿真平臺,其次在此基礎上研究了MZM調(diào)制非線性對于系統(tǒng)的影響,主要包括偏置點與調(diào)制電壓選取、不同子載波數(shù)、不同調(diào)制格式下的系統(tǒng)影響,最后提出了使用光I/Q調(diào)制結(jié)構(gòu)代替雙驅(qū)動調(diào)制器以實現(xiàn)單邊帶DD-OFDM系統(tǒng)。3.研究了CO-OFDM系統(tǒng)中的發(fā)射端調(diào)制結(jié)構(gòu)與脈沖成形的影響。首先介紹了CO-OFDM系統(tǒng)典型的調(diào)制方法;其次提出了使用預失真電路和雙驅(qū)動調(diào)制器來代替?zhèn)鹘y(tǒng)的光I/Q調(diào)制器的方法,經(jīng)過數(shù)學原理推導以及仿真分析對比說明預失真方法具有較好的性能和可用性;最后對通常使用的脈沖成形進行了對比分析得到使用平方根升余弦成形濾波使得系統(tǒng)具有較好的性能。4.對OFDM與WDM結(jié)合的系統(tǒng)進行了簡單的分析,說明了OFDM技術與WDM技術相結(jié)合在長距離大容量光纖通信系統(tǒng)中有應用潛力。
[Abstract]:With the increasing demand of network transmission capacity, the transmission requirements of optical communication networks are becoming more and more high. At the same time, with the development of digital signal processing technology and integrated circuit, OFDM (orthogonal Frequency Division Multiplexing) technology has attracted more and more attention. The introduction of orthogonal frequency division multiplexing technology into optical communication is a hot topic in recent years. Combining the advantages of orthogonal frequency division multiplexing and optical fiber communication technology, optical orthogonal frequency division multiplexing technology can construct high spectral efficiency and large capacity. The optical orthogonal frequency division multiplexing system can be divided into direct detection optical orthogonal frequency division multiplexing system (DD-OFDM) and coherent detection optical orthogonal frequency division multiplexing system CO-OFDM.The optical orthogonal frequency division multiplexing can be combined with wavelength division multiplexing technology. The optical orthogonal frequency division multiplexing (OOFDM) system has excellent performance, which makes the optical orthogonal Frequency-Division Multiplexing (OOFDM) technology in long-distance communication. Optical access network and other applications have great potential, but the modulator and transmitter modulation structure used in the system directly affect the performance of the system. This paper analyzes the modulation characteristics of modulator and the effect of the modulation structure of the transmitter on the system performance, and optimizes its structure according to the application scenes of each system. The main contents of this paper are as follows: 1. The basic principle of OFDM technology is introduced. The realization methods and characteristics of common optical OFDM systems are summarized. Secondly, the influence of nonlinear modulation of MZM in DD-OFDM system is studied and the baseband SSB modulation is optimized by using optical I / Q modulation structure. Firstly, the typical structure of DD-OFDM system is introduced. And the single sideband DD-OFDM simulation platform is built. Secondly, the influence of MZM modulation nonlinearity on the system is studied, including the selection of bias points and modulation voltages, the number of subcarriers and the effects of different modulation formats. Finally, the optical I / Q modulation structure instead of the double drive modulator is proposed to realize the SSB DD-OFDM system. The effects of the transmitter modulation structure and pulse shaping in the CO-OFDM system are studied. The typical modulation methods of the CO-OFDM system are first introduced. Secondly, the method of using predistortion circuit and dual-drive modulator to replace the traditional optical I / Q modulator is put forward. The mathematical principle derivation and simulation analysis show that the predistortion method has good performance and availability. Finally, by comparing and analyzing the pulse shaping used in common use, it is found that using square root raised cosine shaping filter makes the system have better performance. 4. The system combining OFDM and WDM is simply analyzed. The application potential of the combination of OFDM technology and WDM technology in long distance and large capacity optical fiber communication system is explained.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.53

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相關期刊論文 前1條

1 張軍;陳明;陳林;成運;;光OFDM系統(tǒng)中調(diào)制器最優(yōu)偏置的研究[J];光通信技術;2013年03期

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本文編號：1681903