华南理工大学学报(自然科学版) ›› 2013, Vol. 41 ›› Issue (1): 47-51.doi: 10.3969/j.issn.1000-565X.2013.01.007

• 电子、通信与自动控制 • 上一篇    下一篇

短码长LT 码的快速信度传播解码法

詹奇聪 杜明辉 刘东   

  1. 华南理工大学 电子与信息学院, 广东 广州 510640
  • 收稿日期:2012-05-18 修回日期:2012-09-28 出版日期:2013-01-25 发布日期:2012-12-03
  • 通信作者: 杜明辉(1964-),男,教授,博士生导师,主要从事医学信号处理、图像重建等研究. E-mail:ecmhdu@scut.edu.cn
  • 作者简介:詹奇聪(1986-),男,博士,主要从事信道编码及视频传输研究. E-mail:zhan.qicong@mail.scut.edu.cn
  • 基金资助:

    国家自然科学基金资助项目(60972133);广东省自然科学基金团队项目(9351064101000003);广东省能源技术重点实验室项目(2008A060301002)

Fast Belief Propagation Decoding in the Short Length LT Codes

Qi-cong Zhan   

  • Received:2012-05-18 Revised:2012-09-28 Online:2013-01-25 Published:2012-12-03
  • Contact: 杜明辉(1964-),男,教授,博士生导师,主要从事医学信号处理、图像重建等研究. E-mail:ecmhdu@scut.edu.cn
  • About author:詹奇聪(1986-),男,博士,主要从事信道编码及视频传输研究. E-mail:zhan.qicong@mail.scut.edu.cn
  • Supported by:

    国家自然科学基金资助项目(60972133);广东省自然科学基金团队项目(9351064101000003);广东省能源技术重点实验室项目(2008A060301002)

摘要: 无码率码在广播传输中使用时,信道质量突然下降会导致较大突发性错误并使解码器解码效率降低. 为改善此情况,文中提出在短码长LT 码解码中采用快速信度传播(FBP)解码法. 该方法基于交换启发式原理,对接收到的信号立即进行处理,并快速转化为三角矩阵,不仅提高了解码的成功率而且提高了解码速率.由分析和仿真实验可知:FBP解码法的解码成功率较传统的高斯消元解码法和信度传播解码法有极大的提高;当信源信号长度为128b 时,FBP 解码法的解码成功率较传统的信度传播解码法有大幅提高;FBP解码法的解码计算复杂度与解码耗时都优于高斯消元解码法.

关键词: 无码率码, LT 码, 信度传播解码法, 高斯消元解码法

Abstract:

In wireless transmission, the sudden declination of channel quality would result in the rise of error percentage, when a certain number of coded symbols have been received the input symbols are used to be decoded, which would slow down the decoding speed. Hence, to improve the success probability and speed of partial decoding of short code length LT codes, in this paper, we propose the Fast Belief Propagation (FBP) decoding algorithm, which uses the swap heuristic method and the transformation of the triangular matrix not only to enhance the decoding success proportions but also to reduce the decoding delay. According to analysis and experiment, FBP decoding algorithm is better than the conventional methods, Belief Propagation (BP) and Gaussian Elimination (GE). In the simulation, while the length of the source symbols is 128 bits, the probability of the FBP decoding is 48.09 percent higher than traditional ones at the most and its decoding complexity and time consumption are less than GE.

Key words: rateless codes, LT codes, belief propagation, gaussian elimination

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