Algorithm Design And Realization Of Event Monitoring And Fiber Perturbation Location In OTDR System

With the sustainable development of science and technology and the improvement of human living standards,the communication industry as an important support industry has also rapid development.Optical fiber communication as the most efficient way in all variety of communication have been widely used in all walks of life.The transmission of optical signal are mainly through optic cable,while the optic cables are usually in the underground submarine or other outdoor areas,the bending or damage of optic fiber may be affect the transmission of communication signals.So in order to ensure the stability and safety of optical signal transmission,we must locate the fault location and type timely and accurately in the event of failure of transmission to ensure the normal operation of the entire optical fiber communication system.In order to solve the problem that the traditional artificial fiber fault troubleshooting is low accuracy and spend lots of time,this paper has studied the method of optical fiber fault detection and location analysis,and designed a automatic precision fiber fault judgment and positioning system——OTDR event detection and fiber disturbance algorithm system.In this paper,we first compare the various methods of the analysis of fiber signal.According to the actual situation of the signal,we choose the wavelet analysis as the means to process the data.Then we introduce the method of constructing the wavelet and the principle of wavelet denoising,laying the foundation for the subsequent signal processing.Then the optic fiber on-line detection system is briefly introduced,and the main features of OTDR are analyzed.After we deciding to use the wavelet transform method to process the signal,the appropriate wavelet basis and scale are selected according to the actual requirement,and the threshold denoising method is selected to processing the data.After analyzing the return data of the OTDR,we analyze the different characteristics of the reflection event point and the non-reflection event,and then design the different event identification algorithm,that is,the reflection event point adopts the wavelet decomposition threshold location method,the non-reflection event Point using the slope combination threshold method.By comparing the shortcomings of OTDR technology,the paper draws out the POTDR technology which is sensitive to the disturbance signal.Based on the wavelet denoising,a POTDR optical percussion point disturbance monitoring algorithm is designed.And the algorithm sets the upper and lower thresholds by segment to quickly detect the specific position of the perturbation point.Finally,the whole algorithm is transplanted to STM32 for testing the actual fault and disturbance localization system,then complete the design of the OTDR module analysis and automated detection system.