基于短码长的喷泉码度分布设计  

Fountain Codes Degree Distribution Design Based on Short Code Length

作　　者：敖珺[1] 卢亚军[1] 马春波[1] 

机构地区：[1]桂林电子科技大学信息与通信学院,桂林541004

出　　处：《计算机与数字工程》2015年第12期2101-2105,共5页Computer & Digital Engineering

基　　金：国家自然科学基金资助课题(编号:61167006);广西自然科学基金资助课题(编号:2012GXNSFBA053173)资助

摘　　要：度分布对喷泉码的构造具有至关重要的作用,它直接决定喷泉码的编译码性能。对采用鲁棒弧波度分布、截短度分布、固定度分布这三类常用度分布的喷泉码,进行性能分析和仿真,结果表明:译出同等数量码字时,喷泉码的译码开销随着码长的增加而降低;当输入码长K较大时,采用鲁棒弧波度分布的喷泉码的译码开销最小,而码长K较小时,采用截短度分布的喷泉码所需的译码开销最小。考虑到实际应用中有效性和可靠性,构造了一种用于短码长的优化度分布。仿真结果表明,在相同译码开销情况下,优化度分布的译码成功概率相比于传统的截短度分布提高了一个数量级以上。Degree distribution is of vital importance to the construction of fountain codes.It determines the performances of coding and decoding directly.In this paper,the performances of rubust solition distribution,chopped degree distribution,and fixed degree distribution are analyzed and simulated.The result shows that the cost of decoding decreases as the length of codes increases giving the same number of code words.The cost of decoding is minimized by rubust solition distribution when the input code length is large,and when the input code length is small,it is chopped degree distribution＇s turn to play that role.Considering the effectiveness and reliability in practical applications,an optimized degree distribution which applies to short codes is designed.The simulation shows that the probability of correct decoding of the optimized degree distribution increases by one order magnitude comparing to chopped degree distribution when decoding of those distributions cost the same.

关 键 词：喷泉码 无码率 LT码 度分布 

分 类 号：TN43[电子电信—微电子学与固体电子学]