The Research Of Communication Opticalber Fault Diagnosis Based On OTDR Curve

With the rapid development of the communication industry, optical fiber is one of important the most ways of communication transmission, has been widely used, at the same time, we have higher requirements about the efficient, safe and stable of the fiber equipments. Optical cable lines are taken as the main part of optical fiber transmission, any fractures and damages of optical cables will seriously affect the operation of the whole optical network. Cable must be repaired rapidly, so when the fault happens, must determine the type and location of faults as soon as possible, so as to repair the fault fiber and ensure normal communication of optical network.At present, there are certain research about the optical fiber fault detection and fault location, but fault location is not accurate. In order to improve the efficiency of the maintenance of optical fiber, it is necessary to improve the optical fiber fault detection technology, make it develop towards intensification and automation. Optical fiber fault diagnosis and locating module is the difficulty in this research. The methods of OTDR test curve analysis in fault diagnosis system are not accurate, therefore the method of OTDR test curve analysis is the most important part in this paper.In this paper, firstly, introduce the optical communication technology, OTDR technology and its detection principle, analysis of OTDR event type, compare the existing method of signal analysis. Secondly, based on the former discussion, respectively study the mathematical theory of signal analysis based on wavelet transform and the mathematical theory of signal analysis based on Hilbert Huang transform. Thirdly, through simulation, respectively take the wavelet transform to anylysis the OTDR wave data and Hilbert Huang transform to anylysis the OTDR wave data, determines wavelet anlysis basis function and scales of anlysis, make sure the scales of IMF. Through the compartion of the anlysis results, points out the advantages and disadvantages of every method and their application environment. Finally, the wavelet analysis method is applied to the practical fault diagnosis system, finish the OTDR anlysis module, results show the accuracy of OTDR curve analysis based on wavelet transform, compared with the real data, wavelet transform mothod is better, it will have widely application prospect.