FEC编码在高速光通信系统中的应用与性能分析

高速光纤通信系统的研究是当前光通信领域的一大热点,信道编码技术是其中的一项关键技术。文章首先介绍了前向纠错（FEC）编码技术及其在光通信系统中的应用,然后描述了ITU-T G.709中定义的FEC帧的具体格式,数学推导了FEC编码给带来的误码率改善,并列出了具体的计算结果。最后通过实测两款具有FEC数字包封功能的芯片,给出了其在系统传输中的误码率与光信噪比的关系曲线,验证了前向纠错功能

Synthesis and Characlerization of Poly(p-phenylene vinylene) Substitute by Alkoxyl Groups

［中文文摘］利用脱氯化氢的方法合成了聚(2-甲氧基-5-己氧基)对苯乙炔(PMOHOPV)、聚(2-甲氧基-5-辛氧基)对苯乙炔(PMOCOPV)、聚(2,5-二丁氧基)对苯乙炔(PDBOPV)、聚(2,5-二己氧基)对苯乙炔(PDHOPV)、聚(2,5-二辛氧基)对苯乙炔(PDCOPV)等5种聚合物发光材料.通过核磁和红外表征了它们的结构.通过热失重曲线考察了它们的热稳定性.并从温度、催化剂、反应时间、烷氧基取代等方面考察了对聚合物溶解性、分子量、发光性能等的影响.发现可以通过催化剂的用量来改变聚合物分子量,聚合物的分子量与聚合物的溶解性成正比.［英文文摘］Five kinds of PPV derivatives(poly(2-methoxy-5-hexyloxy1,4-phenylene vinylene)(PMOHOPV),poly(2-methoxy-5-octyloxy-1,4-phenylene vinylene)(PMOCOPV),poly(2,5-dibutyloxy-1,4-phenylene vinylene)(PDHOPV),poly(2,5-dihexyloxy-1,4-phenylene vinylene)(PDHOPV),poly(2,5-dioctyloxy-1,4-phenylene vinylene)(PDCOPV))are prepared by dehydrochlorination process with p-methoxyphenol and p-diphenol as raw materials.In comparison with PPV,the five kinds of PPV derivatives can resolve in organic solvent.The influences of synthesis route and reaction conditions are investigated in detail. The structure of five kinds of PPV derivatives are characterized with FTIR and 1HNMR. The thermal stability and thermo performance are obtained from TGcurves. The molecular weight is measured by GPC. The influence of the amount of catalyst , reaction time , temperature , the length of side group on the solubilityof polymer , molecular weight , performance of UV absorption、photoluminescence and electroluminescence is researched. It is found that the molecular weight of polymer can be changed by the amount of catalyst , at the same time , the solubility of polymer increases with the molecular weight of polymer.国家科技部863计划(2001A313070