一种用于RaptorQ码的降维快速译码算法  

Fast Decoding Algorithm for Raptor Q Code Using Matrix Dimensionality Reduction

作　　者：郭晓[1] 张更新[1] 徐任晖[1] 牛大伟[1] 

机构地区：[1]解放军理工大学通信工程学院,南京210007

出　　处：《电子与信息学报》2015年第6期1310-1316,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(91338201;61032004)资助课题

摘　　要：针对新型高效数字喷泉码Raptor Q码译码复杂度高的问题,利用它是系统码的特性,该文提出一种降维快速译码算法。该算法利用预先计算的逆矩阵,将译码过程中对接收编码约束矩阵的求逆转化为对更小维数矩阵的求逆,以降低译码复杂度。算法译码效果与现有译码算法等价。仿真结果表明,在信道符号删除概率较低(小于0.2)时,该算法的译码速度显著高于现有算法。RaptorQ code is a novel and efficient digital fountain code and its decoder is known to be too complicated. Considering the characteristic of the systematic code, a very fast decoding algorithm can be performed using matrix dimensionality reduction. The algorithm exploits a pre-calculated inverse matrix to achieve dimensionality reduction for the received code constraint matrix. As a result, the decoding complexity is reduced significantly while the failure-overhead curve is still identical to that of the conventional approaches. The simulations show that the decoding speed of the proposed algorithm outperforms the state-of-the-art algorithms, when the erasure probability of the channel is relatively low （less than 0.2）.

关 键 词：译码算法 数字喷泉 RaptorQ码 降维译码 

分 类 号：TN911.22[电子电信—通信与信息系统]