【正文】 沈陽理工大學(xué)學(xué)士學(xué)位論文 I 摘 要 隨著現(xiàn)代通信技術(shù)的迅猛發(fā)展，其應(yīng)用領(lǐng)域已滲入到社會(huì)生活的各個(gè)方面，對(duì)通信系統(tǒng)的數(shù)據(jù)傳輸?shù)目煽啃耘c有效性的要求也隨之增強(qiáng)。在傳輸數(shù)字信號(hào)時(shí)，由于信道的時(shí)變性、衰減性、帶寬資源有限性以及干擾大等特點(diǎn)，再有加性噪聲的影響，勢(shì)必會(huì)造成接收端接收到的信號(hào)存在一定的誤差。為提高無線信道傳輸數(shù)據(jù)的質(zhì)量，應(yīng)該將誤比特率降到最低。信道編碼技術(shù)正是降低誤比特率、提高通信質(zhì)量的主要技術(shù)手段之一。 本文首先系統(tǒng)介紹信道編碼的研究背景及意義、發(fā)展史、應(yīng)用并對(duì) matlab 進(jìn)行概述。接著選取編碼技術(shù)中最常用的種類：線性分組碼、循環(huán)碼、卷 積碼。即分別對(duì)線性分組碼、循環(huán)碼和卷積碼的編碼和譯碼原理進(jìn)行闡述，并基于 matlab 平臺(tái)進(jìn)行仿真。最后，通過對(duì)仿真結(jié)果進(jìn)行分析，證明經(jīng)過信道編碼后，能有效降低信道傳輸?shù)恼`碼率，使通信不論在什么環(huán)境下均能高效、可靠的傳輸數(shù)據(jù)，提高了整個(gè)通信系統(tǒng)的質(zhì)量。 關(guān)鍵詞： 通信系統(tǒng)； 編碼技術(shù)；線性分組碼；循環(huán)碼；卷積碼 沈陽理工大學(xué)學(xué)士學(xué)位論文 II Abstract With the rapid development of modern munication technology, its applications have infiltrated into all aspects of social life, reliability and validity of the data munication system also increases. In practice, the wireless channel is very plex. When transmitting digital signals, due to the timevarying channel attenuation, bandwidth and interference limited resources and other characteristics, and then have an impact additive noise, will inevitably lead to the presence of the signal receiver receives a certain error. To improve the quality of the wireless channel, the bit error rate should be reduced to a minimum. One channel coding technology is to reduce the bit error rate and improve the quality of the main technical means of munication. Firstly, referral channel coding system research background and significance, history, and Matlab application overview. Then select the most monly used coding technology types: linear block codes, cyclic codes, convolution codes. Introduces the basic principles of linear block codes, cyclic codes and convolution codes, and simulation based on MATLAB, the simulation results are analyzed, explained after channel coding, enabling munication no matter what the environment can be efficient and reliable transport data to improve the quality of the munication system. Keywords: munication systems。 coding techniques。 linear block code。 cyclic code。 convolution code 沈陽理工大學(xué)學(xué)士學(xué)位論文 III 目 錄 1 緒論 ...................................................................................................................................... 1 研究背景及意義 .................................................................................................... 1 信道編碼技術(shù)的發(fā)展史 ........................................................................................ 2 信道編碼技術(shù)的應(yīng)用 ............................................................................................ 4 Matlab 概述 ............................................................................................................ 5 2 信道編碼 .............................................................................................................................. 7 信道編碼簡(jiǎn)介 ........................................................................................................ 7 信道編碼的基本原理 ............................................................................................ 8 信道編碼系統(tǒng)模型 .............................................................................................. 10 3 幾種常見的信道編碼 ........................................................................................................ 12 線性分組碼 .......................................................................................................... 12 線性分組碼簡(jiǎn)介 ...................................................................................... 12 線性分組碼的編碼與譯碼原理 .............................................................. 13 線性分組碼的編碼程序及仿真圖 .......................................................... 14 線性分組碼的譯碼程序及仿真圖 .......................................................... 16 循環(huán)碼 .................................................................................................................. 20 循環(huán)碼簡(jiǎn)介 .............................................................................................. 20 循環(huán) 碼編碼和譯碼原理 .......................................................................... 20 循環(huán)碼的編碼和譯碼程序 ...................................................................... 22 卷積 碼 .................................................................................................................... 22 卷積碼簡(jiǎn)介 .............................................................................................. 22 卷積碼編碼原理 ...................................................................................... 23 卷積碼譯碼原理 ...................................................................................... 26 沈陽理工大學(xué)學(xué)士學(xué)位論文 IV 卷積碼編碼程序及仿真圖 ...................................................................... 28 卷積碼譯碼程序及仿真圖 ...................................................................... 31 4 抗噪聲性能分析 ................................................................................................................ 38 設(shè)計(jì)思路 ............................................................................................................... 38 對(duì)線性分組碼誤碼率的分析 ................................................................................ 38 線性分組碼仿真過程源代碼 .................................................................... 38 線性分組碼仿真過程圖 ............................................................................ 40 線性分組碼誤碼率源代碼 ........................................................................ 43 線性分組碼誤碼率仿真圖 ........................................................................ 45 對(duì)循環(huán)碼誤碼率的分析 ........................................................................................ 45 循環(huán)碼誤碼率仿真源代碼 ........................................................................ 45 循環(huán)碼誤碼率仿真圖 ................................................................................ 46 對(duì)卷積碼誤碼率的分析 ........................................................................................ 47 卷積碼誤碼