Applications And Research On SFEC For1OOGb/s WDM System

With the growing information requirements, the development of communicationtechnologies and the emergence of new business type, the demand of bandwidth andcapacity in the optical communication network is more and more high. At present, the100Gb/s Wavelength Division Multiplexing(WDM) optical transmission system can beapplied in commercial. On the one hand, the single channel rate has reached100Gb/s orhas been more than100Gb/s. On the other hand, the high speed processing componentshave been mature. However, with the increasing of the single channel rate the factors in theoptical fiber channel, such as chromatic dispersion, polarization mode dispersion, thenonlinearity effect and so on, makes the signal transmission damage more and moreserious, and then the communication quality can not be guaranteed. Therefore, in order toeliminate the damage in the process of transmission, SFEC(Super Forward ErrorCorrection) with high NCG (Net Coding Gain)is one of the most important measures toimprove system performance in order to eliminate the damage produced in thetransmission.The purpose studied in this paper is to find one SFEC technology, its net coding gaincan achieve above10dB when the channel BER is10E-12. And the research can presentthe actual engineering significance for the super forward error correction in the100Gbit/sWDM system.Firstly, the restricted factors and the technologies in the100Gbit/s WDMlong distance system are introduced. Secondly, the basic concepts of FEC and the usualFEC technologies have been commanded. Thirdly, at the beginning compare the SD(SoftDecision) FEC and the HD(Hard Decision) FEC from the theory, and then simulate somekinds of HD and SD SFEC with the different redundancies by Matlab. The simulationresults suggest the SD SFEC with20%redundancies, which can get higher NCG andeasily implement, can be applied in100Gb/s WDM system. By the simulation the papershows that LDPC(Low Density Parity Check Code) is one of the SD FEC technologieswith the most optimal performance. To make up the defect of the error floor existing in LDPC and obtain the higher NCG, this paper puts forward the soft decisionLDPC(9216,7936)+RS(992,956) with the total redundancy20.5%, the NCG of SFECwhich proposed in the paper is11dB. Fourthly, perform a Back-to-Back system test and along distance transmission test making use of the100G OTU4module developed byFiberhome. Through the analysis of the theory and the experiment results, the SFECproposed in this paper can meet the requirement of100Gb/s WDM system.