分布式无标度LT码

LT码是喷泉码的一种,在删除信道中性能优越,分布式喷泉码多信源多中继的特性适合用于深空通信中。无标度网络（SF network）具有平均路径（APL）长最小的特性,非常适合喷泉码的度分布设计需求。首先介绍了LT码的编译码算法,然后对无标度网络和基于无标度网络的SF-LT码度分布设计进行了详细分析和优化,最后在删除信道条件下,选取码长较短、删除概率较小的情形对分布式二信源SF-LT码进行仿真分析,仿真结果表明,与LT码相比,分布式SF-LT码具有更好的性能。

Distributed Scale-free LT Codes

LT code is one of the fountain codes which performs well in erasure channel. The characteristics of multi sources and multi relays make distributed fountain codes fit for deep space communications. Scale -free network has the characteristic of the minimum average path length which makes it perfect for the design requirement of degree distribution in fountain codes. The encoding and decoding algorithm of LT codes is introduced in this paper first, then the design of degree distribution in scale-free networks and SF-LT codes based on the scale-free network is analyzed and optimized. At last, under the condition of erasure channel, the simulation of SF-LT codes with distributed binary sources under shorter code length and lower erasure probability is done. The result shows that distributed SF-LT codes have better performance than LT codes.