利用LDPC编码冗余位译码的恢复性.docx

Error! No text of specified style in document.摘 要随着信息化的发展，人们对信号传输的要求越来越苛刻一方面人们要减少成本加快信息传输速率，一方面还要加强信号可信度，所以对于信道编码方法的研究对信号最后的性能至关重要本文首先从编码思想入手，介绍了信道编码的多种分类和基本理论然后具体介绍了一种常见的优秀码，线性分组系统码即是 LDPC 编码接着着重讨论了该编码在编码性能上的优势，并根据编码理论校验矩阵编码恒等为零，和系统码信源位置保持一致的性质，用 Gallager 规则矩阵生成法和比特填充法生成了两种LDPC 编码之后为了观察编码的恢复性能，用 BP 译码方式估值，而用Punctured LDPC 方式恢复系统码 最后通过 matlab 仿真和理论分析两个方面研究了 Punctured LDPC 译码恢复方式的理论可行性和适用条件发现 Punctured LDPC 译码不能良好的恢复码率高于0.5 的编码，所以存在一定局限性关键词：系统码 Gallager 规则矩阵生成法 比特填充法 BP 译码 Error! No text of specified style in document.ABSTRACTWith the development of information technology, people's demands for signal transmission become increasingly harsh. On the one hand, people want higher transmission rate but reduce the cost. On the one hand, it is necessary to strengthen the credibility of the signal. So the research on the method of channel coding is very important.Firstly, this paper begins with the coding theory, and introduces the variety of channel coding and basic theories. Then we introduced a kind of common excellent code, the code of linear block system, LDPC code. Then we emphasized that the code in the coding performance advantage, according to the coding theory that the parity check matrix of the code is always zero, and the location of code system keep the same. We use Gallager Rule matrix generation method and Bit Filling Method to generate the two LDPC codes. In order to observe the recovery performance of the coding, We used BP decoding method and the Punctured LDPC to recover the system code.Finally, we simulation and analysis through MATLAB. We found that the recovery rate of Punctured LDPC decoding has some limitations. It doesn`t work when transmission rate higher than 0.5. key word: The generation of code Gallager Rule BP decoding目 录 i目 录第一章 编码介绍 .............................................................................................11.1 信道编码的介绍 ..........................................................................................................11.1.1 概述和模型 ...........................................................................................................11.1.2 主流道编码类别的介绍 .......................................................................................31.2 信道编码理论 ..............................................................................................................41.2.1 编码理论介绍 .......................................................................................................41.2.2 编码译码原则 .......................................................................................................5第二章 LDPC 码基础和编码 ........................................................................72.1 LDPC 码的定义与性质 ............................................................................................72.1.1 线性分组码 ..........................................................................................................72.1.2 LDPC 码的定义与其描述 .................................................................................92.2 LDPC 码的节点和 TANNER 图 ..................................................................................102.2.1 校验矩阵的 Tanner 图 ....................................................................................102.2.2 度数分布和循环 ..............................................................................................112.3 规则 LDPC 码和不规则 LDPC 码 ...........................................................................12第三章 LDPC 和 AWGN 信道后的接收 ...................................................143.1 H 矩阵的构造 ............................................................................................................143.1.1 Gallager 构造法生成规则 LDPC 码校验矩阵 ..................................................143.1.2 比特填充法构造非规则 LDPC 码校验矩阵 ..................................................153.2 LDPC 基于高斯消去的直接编码 .............................................................................183.3 经过 AWGN 信道调制解调信号 .............................................................................19第四章 LDPC 译码的思想 ..........................................................................214.1 树图与校验方程关系 ................................................................................................214.2 LDPC BP 译码算法 ...................................................................................................22第五章 对 PUNCTURED LDPC 介绍 ........................................................265.1 PUNCTURED LDPC 恢复思想和理论依据 ..............................................................265.2 利用 PUNCTURED LDPC 译码方式恢复还原信源信号 ...........................................27ii 目 录第六章 仿真程序流程分析 .........................................................................296.1 H 校验矩阵 ................................................................................................................296.2 相似三角矩阵求冗余编码 .......................................................................................316.3 AWGN 信道加噪及其调制信号 ..。