通信学报 ›› 2021, Vol. 42 ›› Issue (9): 31-42.doi: 10.11959/j.issn.1000-436x.2021155

• 学术论文 • 上一篇    下一篇

采用定长节点分类窗口的低误码平台LT编码算法

宋鑫1, 程乃平2, 倪淑燕2, 廖育荣2, 雷拓峰1   

  1. 1 航天工程大学研究生院,北京 101416
    2 航天工程大学电子与光学工程系,北京 101416
  • 修回日期:2021-06-30 出版日期:2021-09-25 发布日期:2021-09-01
  • 作者简介:宋鑫(1995− ),男,山西临汾人,航天工程大学博士生,主要研究方向为信道编码、信道均衡、稀疏码分多址技术等
    程乃平(1962− ),男,陕西扶风人,博士,航天工程大学研究员,主要研究方向为卫星信号处理、正交频分复用技术、信道编码等
    倪淑燕(1981− ),女,河北清河人,博士,航天工程大学副教授,主要研究方向为阵列信号处理、正交频分复用技术等
    廖育荣(1972− ),男,四川德阳人,博士,航天工程大学研究员,主要研究方向为航天测控技术、卫星信号处理技术等
    雷拓峰(1998− ),男,陕西西安人,航天工程大学博士生,主要研究方向为正交频分复用技术、稀疏码分多址技术、信道编码等
  • 基金资助:
    国家自然科学基金资助项目(61805283)

Low error floor LT coding algorithm by using fixed-length node classification window

Xin SONG1, Naiping CHENG2, Shuyan NI2, Yurong LIAO2, Tuofeng LEI1   

  1. 1 Department of Graduate Management, Space Engineering University, Beijing 101416, China
    2 Department of Electronic and Optical Engineering, Space Engineering University, Beijing 101416, China
  • Revised:2021-06-30 Online:2021-09-25 Published:2021-09-01
  • Supported by:
    The National Natural Science Foundation of China(61805283)

摘要:

为了解决传统 LT 码在加性白高斯噪声(AWGN)信道中存在高误码平台的问题,提出了一种改进的编码算法。该算法利用定长分类窗口标记度数值相对较小的信息节点,并使这些节点频繁地参与编码过程,从而使其获得足够高的可靠性。为设计最优的算法参数组合,首先,分析了 LT 码的误比特率(BER)性能和误码平台的成因,引入理论 BER 下界作为第 1 个约束条件。其次,设计了外信息增益损失比(GLR)以衡量算法的收敛性,并将最大化 GLR 值作为第 2 个约束条件。最后,分析了不同参数对算法效率和编码复杂度的影响,指出了参数的优先选取原则,并作为第3个约束条件。仿真结果表明,与传统LT码相比,所提算法可将误码平台降低3个数量级;此外,所提算法也能够实现优于对比LT码的BER性能。

关键词: 信道编码, 喷泉码, 收敛性, 误比特率

Abstract:

To solve the problem of high error floor for LT codes in additive white Gaussian noise (AWGN) channels, an improved coding scheme was designed.A fixed-length classification window was used to sort out the information nodes with relatively small degrees.Then these nodes would be forced to participate in the coding process frequently, so that they could obtain sufficiently high reliability.To design the optimal parameters, firstly, the bit error rate (BER) performance of LT codes and the cause of the error floor were analyzed, and the theoretical BER lower bound was introduced as the first constraint.Secondly, the extrinsic information gain loss ratio (GLR) was designed to measure the convergence behavior of the improved LT code, and maximizing the GLR was denoted as the second constraint.Finally, the influence of different parameters on algorithm efficiency and coding complexity were analyzed, and the principle of priority selection of parameters was pointed out as the third constraint.The simulation results show that compared with the conventional LT code, the proposed algorithm can reduce the error floor by nearly three orders of magnitude.Besides, the designed LT code outperforms the existing LT codes in literature in terms of bit error rate (BER) performance.

Key words: channel coding, fountain code, convergence, bit error rate

中图分类号: 

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