【作者】 王艳萍；

【导师】 胡贵军；

【作者基本信息】 吉林大学 ， 电子与通信工程（专业学位）， 2016， 硕士

【摘要】 随着全球通信网络数据传输技术的不断发展,一些流媒体业务如高清电视、在线直播、远程教育等将成为人们生活中必不缺少的一部分。此外,云计算、在线游戏(包括云游戏)、视频聊天、社交网络、博客、文件分享等等也开始走进人们的生活。因此,人们对带宽的需求越来越大,而现有的通信系统容量在不久的将来将达到饱和状态。为了避免“带宽耗尽”局面的发生,人们提出了诸如波分复用技术、偏振模复用技术以及正交频分复用技术等多种新型通信技术来提高现有单模光纤系统的通信容量。但由于单模光纤固有的非线性效应与放大器自发辐射噪声的限制,使得系统容量越来越接近香农极限。为此,人们又提出了一种新的扩容技术—模分复用技术。模分复用技术的基本思想是利用少模光纤中彼此正交且独立稳定的不同模式分别作为不同的传输信道,每个信道各自承载信息,成倍地增加了系统的传输容量。与此同时,高维调制技术因为其较高的频谱效率和渐进功率效率进入研究者们的视线。高维调制信号在空间是一个整体,而不再像传统的调制格式那样在两个维度进行优化,比如四维调制是在四维空间进行优化,即两个正交的偏振态和同相正交分量,并且不能够被分解成两个独立的二维信号。本着同时从传输技术和信号发送端调制技术两个方面来提升系统的传输性能和传输容量,本文尝试将模分复用技术和高维调制两者结合,研究了基于高维调制的模分复用通信技术。论文的具体工作如下:首先,介绍了模分复用系统的基本结构,论述了系统结构的组成部分。然后论述了模分复用通信的三个关键技术,分别是少模光纤技术、模分复用/解复用技术以及接收端的信号处理技术。其次,论述了高维调制技术的基本原理。详细介绍了产生高维调制信号的三种方法:时域混合方法、编码方法以及球填充方法,并对高维调制的两个关键技术:星座点选取技术和映射技术做了详细的论述。最后给出高维调制的系统框图,建立了高维调制的仿真系统。再次,利用第三章所提到的星座点选取技术和映射技术来产生系统所需的高维调制信号,根据模分复用系统原理,建立基于高维调制的模分复用系统。然后从信噪比、传输距离以及模式耦合三个方面对高维调制信号和传统QPSK信号进行性能比较分析,验证了基于高维调制的模分复用系统的优势。最后,对基于高维调制的模分复用系统接收端的信号处理技术做了仿真研究。采用频域补偿的方法对色度色散进行补偿,利用恒模算法补偿了偏振模色散,利用独立成分分析算法对模式耦合带来的损伤进行了补偿,分析了运用独立成分分析算法补偿前后系统的性能。更多还原

【Abstract】 With the development of the global communications network data transmission technology, some streaming media services such as HDTV, online broadcast, distance education, people’s lives will become indispensable parts in the near future. Moreover, cloud computing, online games(including Cloud games), video chat, social networking, blog, file sharing, etc. began to enter people’s lives. Now the demand for bandwidth is growing,bandwidth in the near future will reach saturation.In order to avoid the situation of "capacity crunch", a variety of technology such as Wavelength Division Multiplexing(WDM), Polarization Division Multiplexing(PDM) and Orthogonal Frequency Division Multiplexing(OFDM) have been proposed. However, most of these technologies are based on Single Mode Fiber Communication System.The capacity of SMF is sestricted by the nonlinear effects and amplifier spontaneous emission noise inherent, making the system more and more close to the Shannon capacity limit. To this end, it has proposed a new expansion technique—mode division multiplexing. The basic idea of mode division multiplexing is use less mode fiber’s orthogonal mode to transmission information, so exponentially increases the transmission capacity of the system. At the same time, high dimensional modulation technique because of its high spectral efficiency and progressive power efficiency into the researchers’ sight. High dimensional modulation no longer like a traditional modulation format as in two dimensions optimized, high dimensional modulation signal in space as a whole, such as four-dimensional modulation in four-dimensional space is optimized, that is, two orthogonal polarization states and quadrature-phase component, and it can not be decomposed into two separate two dimension signal. From signal modulation techniques and transmission capacity of the transmission system both to improve transmission performance, this paper attempts to combine mode division multiplexing and high dimensional modulation technology. Specific work are as follows:Firstly, introduction the basic structure of the mode division multiplexing system, discusses the components of the system architecture. Then discusses the three key mode division multiplexing techniques of communication, which are few-mode fiber technology, mode division multiplexing / de-multiplexing technology and signal processing technology.Secondly, it discusses the basic principles of high-dimensional modulation techniques. Details of the three methods to produce high-dimensional modulation signal: the time domain mixing process, the coding method and sphere packing method, and introduction the two key technology for high-dimensional modulation: constellation point selected technology and mapping technology into details. Finally, the system block diagram of the high-dimensional modulation, the establishment of high-dimensional simulation system modulation.Again, produce the desired high dimensional modulation signal use the technology of mentioned in Chapter III constellation points selected technology and mapping technology, according to the principle of the mode division multiplexing system, establishment of a high dimensional modulation mode division multiplexing system. Then from the SNR, length and anti-coupled three aspects simulation based on high modulation mode division multiplexing system advantage.Finally, research the high-dimensional modulation mode division multiplexing system’s signal processing technology. Frequency domain compensation method for compensating chromatic dispersion, using constant modulus algorithm,compensated polarization mode dispersion, using independent component analysis algorithm compensation the injuries caused by mode coupling, Analysis the performance before and after the algorithm use.更多还原