喷泉码作为一种信道编码是解决大气对自由空间光通信干扰的重要技术, 而度分布是影响喷泉码性能的关键因素。针对喷泉码的度分布, 首先从原理上分析了鲁棒谷子分布和固定度分布在性能上的不足, 之后改进了固定度分布函数, 提出了一种将滑动鲁棒谷子分布和改进的固定度分布这2种度分布相结合, 并通过一个比例系数进行连接的新型联合度分布设计方案。仿真结果表明, 提出的联合度分布的译码性能要远远高于鲁棒孤子分布和固定度分布。

As a kind of channel coding, fountain code is an important technique to solve the interference of atmosphere on free space optical communication. Degree distribution is a key factor affecting the performance of fountain code. In the light of the degree distribution of fountain code, robust soliton distribution and fixed degree distribution is firstly analyzed from the principle and the deficiency on the performance, after that, the fixed degree distribution function is improved, then a new joint degree distribution design is proposed to combine the moved robust soliton distribution with the improved fixed degree distribution by a proportion ratio. The simulation results show that the decoding performance of the joint degree distribution proposed in this paper is much higher than the robust soliton distribution and fixedness distribution.