基于修正正态分布的喷泉编码  

Fountain codes based on the modified normal distribution

作　　者：张茗茗[1] 周诠[1] 

机构地区：[1]西安空间无线电技术研究所空间微波技术国家级重点实验室,陕西西安710100

出　　处：《电子设计工程》2015年第19期89-93,96,共6页Electronic Design Engineering

基　　金：国家自然科学基金(61372175);国家重点实验室基金(9140C530403130C53192)

摘　　要：针对喷泉编码的原始分组的度分布的统计,提出一种基于修正正态分布的编码算法。该方法提出两种统计模型,然后将编码简化为两个多重伯努利分布,发现当分布数目增大时,可以简化为正态分布。在这两种分布下,会有原始分组出现欠利用和过利用的情况。通过计算出这两个伯努利分布的期望值,并利用大量的仿真,统计其方差,得到度分布的置信区间。在编码过程中,能够自适应地将原先欠利用和过利用的部分进行调节,使得每个原始分组对于编解码的贡献趋于一致,提高纠错性能。实验表明,本文算法在高斯信道和删除信道下,与常规的喷泉编码相比较,误码率明显下降。An encoding algorithm based on the modified normal distribution is proposed for the statistics of the degree distribution in the original Fountain codes. Two mathematical modelsare put forward to simplify the codes to two multiple bernoulli distributions, and it＆#39;s found that the two distributions can be simplified as normal distributions when the degree numbers increase. In the condition, the lack of use and the abuse of use will happen to the normal groups. The confidence intervals of the degree distributions are obtained when the expectationsof the two bernoulli distributions are calculated and the variances are counted by the extensive simulation. During the encoding process, the parts of the lack of use and the abuse of use can be adaptive adjusted that the contributions to the encoding and decodingprocedure tend to be uniform in the each of the originalgroups with an improvement in the decoding. The experimental results show that the proposed scheme has a significant decrease in the bit error rate in the Gaussian channel and the erasure channel compared with the present Fountain codes.

关 键 词：喷泉编码 修正正态分布 编码算法 高斯信道 删除信道 

分 类 号：TN911.22[电子电信—通信与信息系统]