Research And Analysis Of The Monitoring Technology For PON Based On OCDM

With the continuous development and commercialization of FTTx, the traffic carried by fiber increases rapidly. If once the link fails, the whole communication network will suffer huge losses. Passive Optical Network as the major implementation of FTTx possesses high efficiency、high bandwidth、support for multi-service access、good interoperability、easy maintenance and many other advantages, effective PON network monitoring system not only reduces network maintenance costs but also improves network reliability. With the continuous development of broadband services and the emergence of large numbers of new business, PON becomes larger and more complex. Because TDM-PON and WDM-PON monitoring technology has been unable to meet the monitoring requirements, at present, the OCDM-PON monitoring technology has been widely studied.The article is based on OCDM-PON monitoring technology, the emphasis research and analysis as follows:1. Analysis several OCDM-PON encoding scheme, and compare encoding implementation with each other, finally research the advantages and disadvantages of encoding.2. Establish a mathematical system model, analysis system impulse response, explore system interference conditions, finally study many factors that impact on system monitoring performance, such as sending pulse power, pulse width, network size etc.3. Explore a new coding scheme, analyze the monitoring principles and the encoding implementation, simulate the performance of the monitoring system, and compare with the 1D coding schemes.4. Analysis user geographic distribution which impact on system monitoring performance and simulate four typical geographical distribution model, analysis the relationship between SIR and the number of users, code weight.The study found that sending pulse power, pulse width, network size and source type have a significant impact on system monitoring performance, through simulating SIR, SNR, SNIR.In the role of different factors, System Monitoring performance will be affected by different dominant factor. For example, when the transmission pulse width is small, SIR is relatively high. In addition, increased pulse width will result in a greater coherence distance. Increased interference will lead to greater beat noise and beat noise will play a leading role, what’s more, when the transmission pulse width wider than the coherence time, the system beat noise get better and SNIR steadily increase.This paper studies the many factors that impact on system performance, which plays an important guiding role in practica l monitoring system and has important reference value to study using different monitoring techniques under different scenarios.