Study And Design Of Physical Layer Of Optical Network Termination Of APON System

The Passive Optical Network based on Asynchronous Transfer Mode (APON) combines the ATM technique with the PON technique, so it can support different services and has the capability to transfer information from service network interface to user network interface changelessly. The FTTH mode of PON is the trend of the broad access network. This dissertation is the summing-up of the design of ONT-the termination of APON system, and emphasizes on the design of physical layer of ONT. The content of this dissertation is as follows:Firstly, this dissertation illustrates the ATM technique and the B-ISDN model, analyzes the structure and the principles of APON system, and then brings forward the layered designing scheme of ONT.Secondly, the CRC technique is analyzed for the data verification of APON system, and then the parallel cell-delineation algorithm and the parallel division algorithm are acquired based on the analysis. The scrambling technique, such as FSS and DSS, is also analyzed according to APON system. The PLL theory and the frequency of the base-band signal are analyzed for the clock recovery function of physical layer.Thirdly, based on the analysis of physical layer's function, the scheme of software and hardware designing implementation, including physical media layer and the TC layer, is brought forward. As for the software, the designing and simulation result of each sub-module of TC layer is analyzed, during the analysis process, some programming and optimization technique is expatiated. As for the hardware, the designing of physical layer circuit is analyzed along with high-speed circuit technique, and the PCB is given at last. At the end, the debugging scheme and the debugging result is given.This project 'Development of the Termination of APON System-ONT' is supported by the high technique fund of JiangSu province, the serial number of the project is BG20011046. The debugging result of Physical Layer indicates that the physical layer functions, especially the TC layer functions with full intellectual property(IP), specified by G.983.1 recommendation has been accomplished well, and the designing goal scheduled is achieved.