Enhancing Iterative Decoding of Polar-like Code Constructions

增强类 Polar 代码结构的迭代解码

• 批准号: 364427907
• 负责人: Professor Dr.-Ing. Stephan ten Brink
• 金额: --
• 依托单位: Institut für Nachrichtenübertragung (INÜ)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/364427907?language=en
• 关键词: Enhancing; Iterative; Decoding; Polar; like

Over the past 60 years, the field of channel coding has evolved from simple error detection through parity bit checking to powerful error correction using dedicated algebraic codes or concatenated coding schemes in conjunction with their respective (iterative) decoders. Those schemes can approach the theoretical capacity limits very closely. While most efforts over the past decade have focused on low-density parity-check (LDPC) codes, or, more recently, their spatially coupled offsprings, this proposal is about studying and enhancing another important development in the field, referred to as "polar codes", introduced by E. Arikan in 2008. He proved that polar codes can achieve capacity of any symmetric Binary Input-Discrete Memoryless Channel (BI-DMC) under Successive Cancellation (SC) decoding for infinite codeword length. As opposed to other "random-like" codes with close-to-capacity performance, polar codes have a very regular (algebraic) structure, opening up the potential for efficient low-complexity hardware implementations; this becomes particularly evident when accounting for the routing overhead in silicon chip technology, which may easily become prohibitive for iterative decoders of state-of-the-art LDPC codes. While it is instructive to realize that polar codes are closely related to Reed--Muller (RM) Codes, their sequential SC decoding algorithm (and thus the selection of the, so called, "frozen" bit channels) follow a quite different approach, leading to many attractive research questions. In this proposal, we seek to find a more comprehensive understanding of belief propagation decoding (BP) for polar codes, to enhance the BER performance of finite-length polar (and polar-like) codes, and to reduce computational complexity and latency of decoding by paving the way to highly parallelized decoder implementations. For this, we need to design polar codes tailored to BP decoding, deviating from the traditional approaches that assume SC decoding. Also, improved analysis tools are essential for better understanding the dynamics of the iterative BP decoder, such as "scattered" Extrinsic Information Transfer (EXIT) charts or density evolution (DE). Moreover, by extending the basic polar code structure, it is possible to obtain novel "polar-like" codes with improved BER performance under iterative BP decoding. First attempts using concatenation/augmentation approaches with auxiliary graph-based codes or applying the concept of spatial coupling turned out to be promising. Combining the BP decoder with a list concept, akin to the successive cancellation list decoder, and the combination of improved BP decoding strategies with channel interfaces such as higher-order modulation for communicating over scalar and vector (MIMO) channels, complement the selection of open research questions for progressing the field.

在过去的60年里，信道编码领域已经从通过奇偶校验位检查的简单错误检测发展到使用专用代数码或级联编码方案结合其各自的（迭代）解码器的强大纠错。这些方案可以非常接近理论容量极限。虽然过去十年的大多数努力都集中在低密度奇偶校验（LDPC）码上，或者最近，它们的空间耦合后代，但本提案是关于研究和增强该领域的另一个重要发展，称为“极化码”，由E. 2008年的阿里坎。他证明了极化码可以实现任何对称二进制输入离散无记忆信道（BI-DMC）在连续消除（SC）解码下的无限码字长度的容量。与具有接近容量性能的其他“类随机”码相反，极化码具有非常规则的（代数）结构，从而开启了高效低复杂度硬件实现的潜力;当考虑到硅芯片技术中的路由开销时，这变得特别明显，这可能很容易对现有技术的LDPC码的迭代解码器造成阻碍。虽然认识到极化码与Reed-Muller（RM）码密切相关是有益的，但是它们的顺序SC解码算法（以及因此所谓的“冻结”比特信道的选择）遵循完全不同的方法，导致许多有吸引力的研究问题。在这项提案中，我们试图找到一个更全面的理解极化码的置信传播解码（BP），以提高有限长度的极化（和类极化）码的BER性能，并通过铺平道路高度并行化的解码器实现，以减少解码的计算复杂度和延迟。为此，我们需要设计针对BP解码的极化码，这与假设SC解码的传统方法不同。此外，改进的分析工具对于更好地理解迭代BP解码器的动态是必不可少的，例如“分散的”外部信息传递（EXIT）图表或密度演化（DE）。此外，通过扩展基本极化码结构，可以获得在迭代BP解码下具有改善的BER性能的新型“类极化”码。第一次尝试使用级联/增强方法与辅助图形为基础的代码或应用空间耦合的概念被证明是有前途的。将BP解码器与类似于连续消除列表解码器的列表概念相结合，以及将改进的BP解码策略与诸如用于在标量和矢量（MIMO）信道上通信的高阶调制之类的信道接口相结合，补充了用于推进该领域的开放研究问题的选择。

项目成果

Belief Propagation List Decoding of Polar Codes

• DOI: 10.1109/lcomm.2018.2850772
• 发表时间: 2018-08-01
• 期刊: IEEE COMMUNICATIONS LETTERS
• 作者: Elkelesh, Ahmed;Ebada, Moustafa;ten Brink, Stephan
• 通讯作者: ten Brink, Stephan

Spatially Coupled LDPC Codes and the Multiple Access Channel

• DOI: 10.1109/ciss.2019.8692899
• 发表时间: 2019-01
• 期刊: 2019 53rd Annual Conference on Information Sciences and Systems (CISS)
• 作者: Sebastian Cammerer;Xiaojie Wang;Yingyan Ma;S. Brink

CRC-Aided Belief Propagation List Decoding of Polar Codes

• DOI: 10.1109/isit44484.2020.9174249
• 发表时间: 2020-01
• 期刊: 2020 IEEE International Symposium on Information Theory (ISIT)
• 作者: Marvin Geiselhart;Ahmed Elkelesh;Moustafa Ebada;Sebastian Cammerer;S. Brink

Decoder-in-the-Loop: Genetic Optimization- Based LDPC Code Design

解码器在环：基于遗传优化的 LDPC 码设计

• DOI: 10.1109/access.2019.2942999
• 发表时间: 2019
• 期刊: IEEE Access
• 影响因子: 3.9
• 作者: Ahmed Elkelesh;Moustafa Ebada;Sebastian Cammerer;Laurent Schmalen;Stephan ten Brink
• 通讯作者: Stephan ten Brink

Decoder-Tailored Polar Code Design Using the Genetic Algorithm

• DOI: 10.1109/tcomm.2019.2908870
• 发表时间: 2019-07-01
• 期刊: IEEE TRANSACTIONS ON COMMUNICATIONS
• 影响因子: 8.3
• 作者: Elkelesh, Ahmed;Ebada, Moustafa;ten Brink, Stephan
• 通讯作者: ten Brink, Stephan