Design Of Line Codes In Gpon System

With the popularization of Internet and the development of wide-band network, Fiber to the home (FTTH) is considered to be an ideal access solution. After ATM passive optical network (APON) and Ethernet passive optical network (EPON), passive optical network (PON) has developed to Gigabit capable passive optical network (GPON). GPON, as a advanced broadband access network technology,is a solution for breaking the bottleneck of network band of access network. While some organizations has started research on this area, this paper chioce line code in GPON as research object.The purpose of this paper is to combine the theoretical research results and practical experiences of line codes, to summarize and analyze the existing line code design algorithms, and finally to design new line codes which have good performance and match with GPON.Reseach was divided into three phases. First phase,the point of work was analyzing the standared protocal and network configuration of GPON, and then talks about the functional structure of G-PON transmission convergence sublayer and its frame structure. Second phase,according to GPON standard, paper deals with scramble code and 8B10B, the two line code technologies which are used in the PON technologies, and their simulation results are also provided. Third phase, proposes a new line code 9B10B which is suit for GPON system.The paper gives detailed description of its constructing processes and simulation results which show that, compared with the tradional scramble code, this new code boasts satisfying DC-balanced characteristics with the maximum running length of 8 and Digital Sum Variation of 12, which can fully meet the requirement of burst receiving. In addition, it has higher bandwith usage in comparison with 8B10B, thus make it more suitalbe for GPON system .