复杂信号相关法实现光纤接入网高精度故障监测

发布时间：2018-08-03 13:07

【摘要】：随着光通信技术的发展,光接入网作为光信号传输的承载单元也实现了大范围铺设,使得人人都可享受到光通信所带来的便利。光接入网中光纤的分布更加密集,光纤到户实现了多根光纤在几米甚至更短间隔的铺设,这就对检测技术提出了很高的要求。若精度无法分辨出这几米内的多根光纤,则光纤一旦发生故障,维护人员可能产生误判,从而造成不必要的人力、物力的浪费。另外,通信速率的提升也使运营商更加重视光纤故障所造成的影响。因此,为了使通信故障造成的损失降到最低,缩短检测和维修时间则是最有效的解决办法。在光接入网故障后的检测维修过程中,维修时间与故障定位的准确性直接相关。光接入网中最常见且最易出现问题的地方就是光纤光缆。维护人员通常使用光时域反射仪进行故障的排查,而该设备使用脉冲飞行法原理,存在故障的定位精度与探测距离矛盾的缺陷,限制了其在远距离测量中的定位精度(范围超过十公里后精度降到几十米甚至上百米),使得维修人员只能在精度范围内搜索排查,导致维修工作无法及时开展。虽然研究者提出了多种光纤故障定位的方法,但很难将远程高精度的定位功能用简易的装置实现。为了严格控制运维成本,运营商急需简单、实用的监测装置才能实现分布日益广泛的光接入网中光纤的维护。近些年来,研究发现相关法探测技术虽然可以实现大范围高精度的故障探测,解决光时域反射仪测量故障存在的缺陷。但该方法对探测信号的要求相当严格:周期性会限制探测距离,信号的带宽会限制探测精度。因此,在相关法探测技术中,探测信号要求具备无周期性、高带宽且产生装置不复杂的条件后才可用于光网络的故障监测。如今的光接入网主要存在三种结构形式:有源光网络、无源波分复用光网络、无源时分复用光网络。由于各网络布线结构与信号传输方式不同,其对监测装置的要求也各有侧重。本论文基于相关法原理,针对这三种网络分别提出了相应高精度监测装置,结构简单,具有良好的应用前景。本文的主要研究内容和创新点如下:1.从现有光纤故障探测技术出发,原理上分析了相关探测技术与其他技术相比的优势,以及该技术对探测信号的要求;2.在有源光网络中,将网络中的通信信号作为探测信号,借助该信号具有的振荡随机且变化速率高的特性,在现有网络中结合相关技术实现了实时的厘米级精度的故障监测、定位功能;3.在无源波分复用光网络中,由于各支路具有特定的波长信息,所以探测信号光谱范围必须覆盖网络所有支路的波长信息,因此我们使用集成度高的超辐射发光二极管,利用其宽光谱及输出信号振荡随机起伏的特性,实验实现了大范围高精度的故障监测;4.在无源时分复用光网络中,由于难以通过信号特征分辨具体支路,所以我们在各支路末端添加反射式光滤波器,滤波器的反射或故障点的菲涅尔反射提供多光反馈,使探测激光器产生混沌激光。该混沌激光信号的外腔时延(位置)信息即反映了反馈点的位置,再由消失的滤波器位置信息和新增的位置信息即可实现故障支路和故障位置的判断,实验中获得了毫米级精度的故障探测。
[Abstract]:With the development of optical communication technology, optical access network (optical access network), as the bearing unit of optical signal transmission, has also realized a wide range laying, which makes everyone enjoy the convenience brought by optical communication. The distribution of optical fiber in the optical access network is more dense, and the fiber to the household realizes the laying of multiple fibers in a few meters or even shorter intervals. If the precision can not distinguish the multiple fibers in these meters, if the optical fiber fails, the maintenance personnel may be misjudged, thus causing unnecessary human and material waste. In addition, the increase of the communication rate makes the operators more aggravating the effect of the optical fiber barrier. Therefore, in order to make the communication malfunction made. The most effective solution is to reduce the loss and shorten the detection and maintenance time. In the process of detection and maintenance after the optical access network fault, the maintenance time is directly related to the accuracy of the fault location. The most common and most likely problem in the optical access network is fiber optic cable. The maintenance personnel usually use the optical time domain reflector. By using the principle of the pulse flight method, the equipment has the defects of the contradiction between the positioning accuracy and the detection distance of the fault, which limits the positioning accuracy in the long distance measurement. The precision is reduced to tens of meters or even hundreds of meters after the range is over ten kilometers. The maintenance personnel can only search and check in the range of precision, resulting in maintenance. It is difficult to carry out the work in time. Although the researchers have proposed a variety of optical fiber fault location methods, it is difficult to implement the remote high precision positioning function with a simple device. In order to control the operation and maintenance costs strictly, the operators need simple and practical monitoring devices to realize the maintenance of optical fiber in the optical access network with a wide distribution in recent years. It is found that the detection technique of correlation method can realize large range and high precision fault detection and solve the defect of optical time domain reflectometry. However, this method is very strict with the detection signal: periodicity will limit the detection distance and the bandwidth of the signal will limit the detection accuracy. Therefore, detection in the correlation method detection technology, detection The signal requires an aperiodic, high bandwidth and uncomplicated condition that can be used to monitor the fault of the optical network. Now there are three main types of optical access networks: active optical network, passive wavelength division multiplexing optical network, passive time division multiplexing optical network. The requirements of the monitoring device are also focused. Based on the principle of relevant methods, this paper puts forward the corresponding high precision monitoring device for these three kinds of networks, which has simple structure and good application prospect. The main contents and innovation points of this paper are as follows: 1. the related detection techniques are analyzed in principle from the existing optical fiber fault detection technology. Compared with other technologies, and the requirement of the detection signal, 2. in active optical network, the communication signals in the network are used as detection signals, with the aid of the characteristics of random oscillation and high change rate of the signal, the real-time centimetre precision fault monitoring is realized in the existing network, and the positioning work is realized. 3. in the passive wavelength division multiplexing optical network, because each branch has specific wavelength information, the spectrum range of the detection signal must cover all the wavelength information of all the branches of the network. Therefore, we use the high integrated ultra radiant light emitting diode to make use of the characteristics of its wide spectrum and the random fluctuation of the output signal. High precision fault monitoring; 4. in the passive time division multiplexing optical network, because it is difficult to distinguish the specific branch from the signal characteristics, we add reflective optical filters at the end of each branch. The reflection of the filter or the Finel reflection of the fault point provides multi light feedback to make the detection laser produce chaotic laser. The chaotic laser signal The time delay (position) information of the external cavity reflects the position of the feedback point, and then the fault branch and the fault location can be judged by the disappearing filter position information and the new position information. The fault detection of millimeter level precision is obtained in the experiment.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN915.63

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