LDPC碼及應(yīng)用研究

論文編號(hào):TX411  論文字?jǐn)?shù):17086,頁(yè)數(shù):38

LDPC碼及應(yīng)用研究
摘  要

差錯(cuò)控制編碼，也稱為信道編碼已經(jīng)廣泛地應(yīng)用在各種通信系統(tǒng)和計(jì)算機(jī)系統(tǒng)中。并且它是移動(dòng)通信系統(tǒng)中的關(guān)鍵技術(shù)之一，LDPC碼是糾錯(cuò)碼中比較出色的好碼。因?yàn)長(zhǎng)DPC碼是最為接近Shannon極限的信道編碼，同時(shí)也是下一代寬帶移動(dòng)通信系統(tǒng)中糾錯(cuò)編碼的主要備選方案。
這次畢業(yè)設(shè)計(jì)主要通過(guò)對(duì)大量文獻(xiàn)的查閱和研究，熟悉LDPC碼的定義和原理；兩種編碼方法基于下三角矩陣的編碼方法和基于近似三角矩陣的編碼方法、譯碼算法以及它和另一種糾錯(cuò)碼Turbo碼的比較，比較它們的性能差異和譯碼復(fù)雜度。LDPC碼在多種領(lǐng)域都有廣泛的應(yīng)用，比如DVB-S2（第二代衛(wèi)星數(shù)字視頻廣播系統(tǒng)）、CMMB（中國(guó)移動(dòng)多媒體廣播）、壓縮圖像傳輸、圖像數(shù)字水印等。通過(guò)LDPC碼在圖像數(shù)字水印系統(tǒng)中的應(yīng)用來(lái)研究基于LDPC碼的水印方案，這個(gè)方案主要是用于提高圖像數(shù)字水印的魯棒性，通過(guò)水印信息編碼對(duì)它的原理進(jìn)行比較全面的研究，從而更深入的了解LDPC碼的在圖像數(shù)字水印系統(tǒng)中的應(yīng)用。
關(guān)鍵詞：差錯(cuò)控制編碼  LDPC碼  Turbo碼  圖像數(shù)字水印

LDPC codes and applied research
ABSTRACT

Error-controlling codes, also called channel coding has been widely applied in various communication system and computer system. And it is the mobile communication system, one of the key technology . LDPC code is comparatively outstanding  good yards. Most closely because LDPC code is the channel coding Shannon limit, but also the next generation broadband mobile communication system error correction coding main alternatives.
The graduation design mainly through a vast amount of literature review and study, familiar with the definition and principles LDPC code; Two kind of coding method based on triangle matrix under the coding method based on approximate triangular matrices and the coding method, decoding algorithm and it and another kind of  Turbo yards of comparison, compare their performance differences and decode complexity. LDPC code in a variety of areas are widely used, For instance (the second generation DVB - S2 satellite digital video broadcast system), CMMB (China mobile multimedia broadcasting), compressed image transmission and digital image watermarking, etc. Through LDPC code in the application of digital image watermarking system based on LDPC code to research the watermarking scheme, This scheme is mainly used to raise the image watermarking robustness, Through the watermark on its principle of coding of more comprehensive study to more in-depth understanding of the digital image LDPC code watermarking system application.
Key words: Error-controlling codes  LDPC codes  Turbo code  image watermarking

目  錄

摘要 Ⅰ
ABSTRACT Ⅱ
1  前言 1
1.1研究背景 1
1.2研究?jī)?nèi)容 1
1.3研究的任務(wù)及目標(biāo) 2
2  差錯(cuò)控制編碼理論 3
2.1差錯(cuò)控制編碼基本概念 3
2.2信道模型和信道容量 6
2.3信道編碼定理 7
3  LDPC碼 9
3.1LDPC碼的概念 9
3.1.1LDPC碼的定義 9
3.1.2LDPC碼的Tanner圖表示 10
3.1.3非規(guī)則LDPC碼 10
3.2 LDPC碼的幾何構(gòu)造 11
3.3 LDPC碼的編碼方法 12
3.3.1基于下三角矩陣的編碼方法
3.3.2基于近似三角矩陣的編碼方法
3.4 LDPC碼的譯碼 14
 4  LDPC碼與Turbo碼的比較 17
 4.1Turbo碼概述 17
 4.2LDPC碼與Turbo碼的比較 19
5  LDPC碼的應(yīng)用 22
5.1LDPC碼應(yīng)用領(lǐng)域 22
5.2LDPC碼在圖像數(shù)字水印系統(tǒng)中的應(yīng)用 23
5.2.1圖像數(shù)字水印技術(shù) 23
5.2.2基于LDPC碼的水印方案 25
6  結(jié)束語(yǔ) 32
參考文獻(xiàn) 33
謝辭 34