一种联合度分布LT码设计

LT码是一类前向纠错信道编码，用于纠正信道分组删除（Packeterasure）。这类编码具有广泛的用途，包括计算机科学、网络传输、媒体存储、大文件下载等等。在LT码的设计中，度分布是成功解码和快速运算的关键。这篇文章展示了一种新的LT码设计，它将弱分布用于前期解码，再将增强型分布用于后期解码。由于弱分布具有低的平均度数，它可以显著地增加编码及解码的速度。同时，增强型度分布具有高的平均度数，能够提高成功解码的概率。通过一系列的仿真，笔者观察到这种设计的编码冗余度和编解码所需的异盛运算量比使用Robustsoliton分布的参考方案降低大约50％。

A Joint Degree Distribution LT Codes Design

LT codes are a class of forward error correction channel codes which are developed to recover channel packet era- sures. They have a multiple of uses in computer science, network transmission, media storage, large file download and so on. In the design of LT codes, the degree distribution is the key to successful decoding as well as fast operation. This pa- per presents a novel design with a weakened distribution for prior decoding and an improving distribution for posterior de- coding. Since the weakened distribution has a low average degree, it substantially increases both the encoding and decoding speed, while the improving distribution has a high average degree that enhances the successful decoding probability. With a series of simulations, we observed that the overhead as well as the XOR operations is cut about 50% compared with the reference design of Robust Soliton distribution.