LDPC码与Polar码的实现相关研究

发布时间：2018-01-27 03:46

本文关键词： LDPC码解码器误差平底解码算法乘积码 polar码　出处：《南京大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着现代数字通信的进一步发展,LDPC码凭借其优异的纠错性能被越来越多的通信标准所采用。2006年由国家广电总局颁布的中国移动多媒体广播标准(CMMB)就采用了LDPC码。本文基于Layered min-sum解码算法,为了降低解码器功耗,提出了一种非规则量化策略,并设计了相应的应用于CMMB标准的解码器及各模块结构。仿真结果表明,该设计方案能够在保证必要吞吐率的前提下减少约35%的计算,从而降低了解码器功耗。目前,LDPC码的研究领域主要围绕着两个大的方面：一是解码器的设计；二是码的性能,尤其是在高信噪比区域,对误差平底的研究。为了克服误差平底,本文针对LDPC-SPC乘积码,提出了一种相应的行列混合迭代解码算法。实验结果表明,该乘积码理论上能够有效降低误差平底,且解码复杂度仅稍有增加,对降低LDPC码误差平底的研究提供了一种可选方案。 Polar码即极化码,是E.Arikan在2007年提出的一种最新的编码技术。在二进制离散无记忆信道条件下,极化码理论上被证明可以达到香农极限。近来,极化码因其接近香农限的性能,且编解码具有较低复杂度,逐渐成为纠错码研究的热点。本文提出了一种简单的基于部分并行输入的极化码编码器的硬件结构实现,有效解决了极化码由于码字过长而编码复杂度较高的问题。最后,本文讨论了极化码的译码算法。由于传统的连续消除译码算法是串行解码,所以实际应用中所需要的长码字会造成很高的解码时延。本文提出了一种改进的连续消除译码算法,这种改进后的译码算法相比于传统的译码算法能减少约一半的译码延迟。而且,仿真结果表明改进后的解码算法在纠错性能上的损失是可以忽略不计的。
[Abstract]:With the further development of modern digital communication. LDPC code is adopted by more and more communication standards because of its excellent error-correcting performance. In 2006, China Mobile Multimedia Broadcasting Standard was issued by State Administration of Radio, Film and Television (SARFT). LDPC code is adopted. This paper is based on Layered min-sum decoding algorithm. In order to reduce the power consumption of the decoder, an irregularity quantization strategy is proposed, and the corresponding decoder and each module structure applied to the CMMB standard are designed. The simulation results show that. The proposed scheme can reduce the power consumption of the decoder by about 35% while ensuring the necessary throughput. At present, the research field of LDPC codes mainly revolves around two aspects: first, the design of decoder; The second is the performance of the code, especially in the high SNR region, the study of the error flat bottom. In order to overcome the error flat bottom, this paper aims at the LDPC-SPC product code. An iterative decoding algorithm for column and column mixing is proposed. Experimental results show that the product code can effectively reduce the error at flat bottom theoretically, and the decoding complexity is only slightly increased. An alternative scheme is provided for the research of reducing the error of LDPC codes at flat bottom. Polar code is called polarization code, which is the latest coding technique proposed by E. Arikan in 2007. In the condition of binary discrete memoryless channel. Polarization codes have been proved to reach Shannon limit theoretically. Recently, polarization codes have low complexity due to their performance close to Shannon limit. This paper presents a simple hardware implementation of polarization code encoder based on partial parallel input. The problem of high coding complexity due to long codewords is effectively solved. Finally, this paper discusses the decoding algorithm of polarimetric code, because the traditional continuous cancellation decoding algorithm is serial decoding. Therefore, the long codewords needed in practical applications will cause a high decoding delay. In this paper, an improved continuous decoding algorithm is proposed. Compared with the traditional decoding algorithm, the improved decoding algorithm can reduce the decoding delay by about half, and the simulation results show that the loss of the improved decoding algorithm in error correction performance is negligible.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.22;TN915.1

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