The Research Of Phy For POF Transmission Link

Plastic optical fiber (POF) is a new type of optical fibers. With the advantages of large core, strong flexibility and easy installation, POF has been one sort of potential alternative transmission media in communication systems of short distance, small and medium capacity. However, compared with glass optical fiber (GOF), POF’s transmission performance is involved in the impacts of large attenuation and limited bandwidth which can not meet the need of communication of long distance and high capacity. Therefore, in the current trends of "light into and copper back" and "triple play", how to reduce POF links’ transmission attenuation and enlarge transmission capacity has been one of the research hotspots for the majority of scientific research institutions and corporations in order to meet people’s rapidly increasing need of bandwidth. In case of these backgrounds, a special physical layer (PHY) for POF transmission links is researched in this paper, an optional forward error correction (FEC) code is integrated into physical coding sublayer (PCS) to provide the function of error correction while improving the linear coding technology in PCS.In the first chapter of this paper, the current research and the development of POF communications at domestic and abroad are investigated, and the main contents of this paper are also given at last.In the second chapter of this paper, the composition of ordinary transmission system, the research of POF and the basic knowledge of PHY are proposed in order to well acquaint with the following parts.In the third chapter of this paper, PCS is mainly researched. The64B/67B encoder followed by the scrambler and gearbox is proposed, which not only obtains lowest possible line bit rate but also good DC-balance and transition-density.In the fourth chapter of this paper, a low density parity check (LDPC) code is used to provide a function of error correction for the type of FEC code in PCS. Firstly, the system constructed gallager (SCG) arithmetic is applied to construct a kind of parity check matrix without4-cycles, and LU decomposition arithmetic is used to design LDPC encoder to achieve linear coding performance and less resources consumption. Secondly, in receiver, the threshold bit flipping (TBF) decoding method is proposed to decode more than one bit at one time of iteration. Finally, a module of synchronizing LDPC code is also designed, and simulation result is proposed.In the last chapter of this paper, the finished research work is concluded, and some research topics of POF in the future study are also proposed.