针对下一代广播通信系统中低密度奇偶校验码的研究和分析

项目名称： 针对下一代广播通信系统中低密度奇偶校验码的研究和分析

项目编号： No.61601286

项目类型： 青年科学基金项目

立项/批准年度： 2017

项目学科： 无线电电子学、电信技术

项目作者： 徐胤

作者单位： 上海交通大学

项目金额： 14万元

中文摘要： QC-IRA结构的LDPC码字由于其描述简单、性能优异且易于编译码器实现，被各大通信标准所采用。而在新一代美国地面数字电视传输标准ATSC3.0技术方案的角逐中，我们设计的两个中高码率码字进入了最后一轮候选名单，目前也正在研制该系统收发端样机。受益于该过程，我们发现演进的广播传输标准对QC-IRA的LDPC码字提出了更高要求。而QC-IRA的LDPC码字技术的现状是：1）现有标准中的低码率码字性能差且文献缺乏系统研究；2）现有译码算法仍存在改进空间；3）HSS译码架构跨层信息不独立，导致无法采用性能优异的译码算法。对此，本项目深入研究1）基于QC-IRA Raptor结构的低码率码字的系统化设计方案；2）一系列变化因子译码算法；3）HSS译码架构的独立性条件及译码算法的修正方法，进一步改进LDPC码字的性能，以期为呼之欲出的下一代中国地面数字电视物理层传输标准的收发端码字方案提供解决方案。

中文关键词： LDPC码字设计；QC-IRA-Raptor码字；变化因子；译码算法；HSS译码架构

英文摘要： QC-IRA structured low density parity check (LDPC) code is adopted by various types of communication standards and systems, mainly because it has good performance and is easy to be described and implemented. While during the competition of technical proposals for the new generation American Terrestrial broadcasting transmission standard (ATSC3.0), we designed and proposed to ATSC3.0 two moderate-high rate LDPC codes which happened to enter into the final round competition as candidate Standard codes. Besides, we are currently designing the prototype hardware for ATSC3.0 transceiver and receiver. Benefiting from the experience, we find out that the evolving broadcasting standards requires QC-IRA structured LDPC codes to have better performance. And the state of the art for QC-IRA LDPC code is as follows: 1) QC-IRA LDPC codes in existing standards with low code rates have poor performance and there is no systematic research work on it in the literature; 2) There are still room for making improvements for existing decoding algorithms; and 3) The cross layer information in HSS decoding structure is not independent, which leads to that many excellent decoding algorithms can not be adopted. To these problems, in this project, we research profoundly 1) a systematic scheme for designing Shannon approaching low code rate QC-IRA Raptor-like LDPC codes; 2) series of variable correction factor decoding algorithms; and 3) the condition for of independence for HSS scheme, and how to modify the good performance decoding algorithm to finally be used by HSS. By getting the good results from these studies, we hope to further improve the performance of LDPC codes, to provide a solution for the LDPC codes at both transceiver and receiver side for china’s next generation terrestrial broadcasting physical layer transmission standard.

英文关键词： Design of Low density parity check code;QC-IRA-Raptor code;variable correction factor;decoding algorithms;horizontal shuffled scheme