一种用于LT码的新型联合度分布设计方法

A design method of novel combined degree distribution for LT code

为提高LT码的性能,提出一种用于LT码的新型联合度分布设计方法。将鲁棒孤子分布和改进的幂律分布结合,利用黄金分割算法对基于联合度分布函数的可译集函数进行优化搜索,找出使LT码具有更好译码性能的参数。仿真结果表明,在二进制删除信道的不同删除概率下,联合度分布与鲁棒孤子分布和无标度LT码相比,具有更好的编译码性能。当删除概率为0时,相较于鲁棒孤子分布,联合度分布译码开销可节省2.23%~7.62%,编译码所消耗的时间缩短9.46%~28.57%。

In order to improve the performance of LT code,a design method of novel combined degree distribution for LT code is proposed.The power-law distribution is combined with robust soliton distribution,and then,based on the ripple function of the combined degree distribution,the golden section algorithm is used to search the appropriate parameters which lead to better decoding performance of LT code.The simulation results show that the proposed combined degree distribution always has the best encoding/decoding performance among the RSD,the scale-free LT1 and the proposed combined degree distribution when the erasure probability is different over binary erasure channel.Compared with RSD,the proposed combined degree distribution saves 2.23%-7.62% overhead and speeds up the encoding/decoding process by 9.46%-28.57%to decode entire input symbols when the channel erasure probability is zero.