广义分布式喷泉码的改进优化算法  

A Modified Optimization Method for Generalized Distributed Fountain Codes

作　　者：邵汉钦[1] 徐大专[1] 张小飞[1] 许生凯 

机构地区：[1]南京航空航天大学电子信息工程学院,南京210016

出　　处：《信号处理》2014年第11期1252-1256,共5页Journal of Signal Processing

基　　金：国家自然科学基金(61471192;61371169;61301108);航空科学基金(20120152001);中国博士后科学基金(2013M541661)资助项目

摘　　要：广义分布式喷泉码是针对多信源单中继网络而提出的一种分布式喷泉编码方案,其采用两步优化算法,对中继和源的度分布分别采用线性和非线性规划进行优化求解。但该优化方法复杂度较高,且优化结果依赖于初始度分布的选取。针对该问题,本文对两步优化算法进行改进,提出了一种新的度分布优化算法。该算法基于非线性规划方程,对源的度分布只需进行一步优化,并避免了选取初值的问题,降低了度分布优化的复杂度。仿真表明,本文提出的改进优化算法能够提高优化的稳健性和可靠性,改善总体译码性能,降低系统的误码率。Generalized distributed fountain codes（GDFC） were proposed as a distributed fountain coding scheme for multi-source single-relay networks. The degree distributions of the relay and sources are optimized by a two-step optimization method using linear and nonlinear programs,respectively. However,the optimization method is with high complexity,and the optimization results depend on the selection of the initial degree distribution. To address this problem,a novel simplified optimization method based on nonlinear program is presented. The proposed method only needs to optimize the degree distributions of the sources and only a simplified one-step optimization is used. Thus,the selection of the initial degree distribution of the sources can be avoided,and the performance can be improved. Compared with the two-step optimization method,the proposed one-step optimization method improves the efficiency and reduces the complexity. Simulations show that the proposed method can enhance the robustness and reliability of the optimization. Simulation results also verify that the bit error rate（BER） can be reduced and the decoding performance of GDFC can be improved.

关 键 词：多信源单中继网络 分布式喷泉码 度分布 非线性规划 

分 类 号：TN911.22[电子电信—通信与信息系统]