电子学报 ›› 2015, Vol. 43 ›› Issue (4): 800-805.DOI: 10.3969/j.issn.0372-2112.2015.04.025

• 科研通信 • 上一篇    下一篇

基于度分布合并和可译集优化的LT码度分布设计方案

雷维嘉1, 张梦1,2, 谢显中1   

  1. 1. 重庆邮电大学移动通信技术重庆市重点实验室, 重庆 400065;
    2. 重庆工商大学融智学院, 重庆 400033
  • 收稿日期:2013-09-22 修回日期:2014-06-26 出版日期:2015-04-25 发布日期:2015-04-25
  • 作者简介:雷维嘉 男,1969年出生,云南元谋人.教授、博士.现主要从事无线通信传输技术的研究.E-mail:leiwj@cqupt.edu.cn;张梦 女,1988年10月出生,重庆渝中人.2014年毕业于重庆邮电大学,获取硕士学位.现主要从事信息管理与信息系统专业教学工作,及信道编码、个人通信等领域的科研工作.E-mail:adamengzhang@163.com
  • 基金资助:

    国家自然科学基金(No.61471076,No.61271259,No.61301123);长江学者和创新团队发展计划(No.IRT1299);重庆市科委重点实验室专项经费

A Design Scheme for LT Codes Degree Distribution by Combining Degree Distributions and Optimizing Ripple Size

LEI Wei-jia1, ZHANG Meng1,2, XIE Xian-zhong1   

  1. 1. Chongqing Key Lab of Mobile Communications Technology, Chongqing University of Posts and Telecommunications, Chongqing 400065, China;
    2. Rongzhi College of Chongqing Technology and Business University, Chongqing 400033, China
  • Received:2013-09-22 Revised:2014-06-26 Online:2015-04-25 Published:2015-04-25

摘要:

喷泉码的度分布对喷泉码的编译码性能有着十分重要的影响.目前常用的度分布在源数据码长较长时具有较好的性能,但在码长较短时,性能有明显下降.本文给出一种LT码度分布的构造方法.该方法先对二进制度分布进行调整,然后将其与鲁棒孤子度分布进行有机结合,再通过优化可译集合值来进一步优化度分布函数,得到一种当源数据为短码长时也有较好性能的度分布,即修正二进制-鲁棒孤子度分布.仿真结果证明,采用这种度分布对源数据进行LT编码时,相比较二进制度分布和鲁棒孤子度分布,其译码性能得到了明显提高,并且码长越短,性能提高越明显.

关键词: 数字喷泉码, LT码, 度分布, 可译集合

Abstract:

The degree distribution has a very important influence on the decoding efficiency of fountain codes.The decoding performance is good when the message size is large,but it drops dramatically when the size becomes smaller,which is the inevitable result of using the existing degree distributions to encode.In this paper,we present a new scheme to design the degree distribution.First,we combine the robust soliton degree distribution with the modified binary exponential distribution and further adjust the degree by optimizing the ripple size.By doing this we can get modified binary robust distribution(MBRD),which can also perform well when the source message size is small.Through simulation experiments,we have verified that MBRD greatly improves the encoding and decoding performances.Moreover,compared with the existing degree distributions,the smaller the source message size becomes,the more evidently the performance is improved.

Key words: fountain codes, LT codes, degree distribution, ripple size

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