【正文】 rees. Established cascade LDPC and RS FEC programs intertwined with enhanced polarization mode dispersion pensation system, to analyze the results showed that the pensation of polarization mode dispersion played a certain effect and improve the bit error rate, and increased the polarization mode dispersion tolerance. Obtained simulation result of at least 6dB BER improvement for 40Gb/s OOK transmission by using PMDC and eFEC. Key words: forward error correction, LDPC codes, PMD, RS codes, Concatenated code 北京郵電大學(xué)碩士學(xué)位論文 3 目 錄 第一章 概述 ..................................................................................................................................... 4 通信和通信系統(tǒng) .................................................................................................................. 4 偏振模色散補(bǔ)償 .................................................................................................................. 4 前向糾錯的發(fā)展歷程 .......................................................................................................... 5 LDPC 碼的應(yīng)用前景 .......................................................................................................... 7 論文的結(jié)構(gòu)安排 .................................................................................................................. 8 第二章 偏振模色散的基本理論 ................................................................................................... 12 偏振光基本概念 .................................................................................................................. 12 偏振態(tài)的表示方法 .............................................................................................................. 12 瓊斯矢量 ....................................................................................................................... 12 斯托克斯（ Stokes）矢量 ............................................................................................ 13 邦加球的表示方法 ....................................................................................................... 14 偏振模色散的產(chǎn)生 ............................................................................................................... 17 偏振模色散補(bǔ)償控制技術(shù) .................................................................................................. 17 光域偏振模色散補(bǔ)償方案 ............................................................................................ 18 偏振模色散補(bǔ)償單元 .................................................................................................... 18 偏振模色散監(jiān)測模塊 ................................................................................................... 19 反饋控制模塊 ................................................................................................................ 19 PSO 算法 .............................................................................................................................. 20 PSO 算法的搜索算法流程 ........................................................................................... 21 PSO 跟蹤算法流程 ....................................................................................................... 22 本章小結(jié) ............................................................................................................................... 23 第三章 LDPC 碼基本原理和編譯碼方法 .................................................................................... 25 前向糾錯技術(shù)概述 ............................................................................................................ 25 分組碼 ................................................................................................................................ 25 低密度奇偶校驗(yàn)碼概述 .................................................................................................... 26 LDPC 碼的分類 ................................................................................................................ 27 LDPC 規(guī)則碼隨機(jī)構(gòu)造方法 ............................................................................................. 27 構(gòu)造規(guī)則碼校驗(yàn)矩陣的要求 ....................................................................................... 27 LDPC 碼基于行分裂和列分裂的構(gòu)造方法 ................................................................. 27 LDPC 碼的譯碼算法 ........................................................................................................ 28 比特翻轉(zhuǎn)譯碼算法 ....................................................................................................... 29 置信傳播譯碼算法 ........................................................................................................ 30 本章小結(jié) .............................................................................................................................. 40 第四章 前向糾錯性能仿真以及在光纖 PMD 補(bǔ)償系統(tǒng)中應(yīng)用仿真 ........................................ 43 LDPC 碼譯碼性能仿真分析 ............................................................................................. 43 LDPC 碼應(yīng)用于 PMD 補(bǔ)償 .............................................................................................. 45 FEC 編碼應(yīng)用于有 PMD 補(bǔ)償器的系統(tǒng) ......................................................................... 46 增強(qiáng)型 FEC 應(yīng)用于有 PMD 補(bǔ)償器的系統(tǒng) .................................................................... 47 本章小結(jié) ............................................................................................................................ 49 攻讀碩士期間發(fā)表論文情況 ......................................................................................................... 51 致謝 ................................................................................................................................................ 52 北京郵電大學(xué)碩士學(xué)位論文 4 第一章 概述 自從出現(xiàn)了人類，就有了伴隨人類的通信系統(tǒng)。 ? 建立了 LDPC 與 RS 級聯(lián)交織的增強(qiáng)型 FEC 方案 并結(jié)合偏振模色散補(bǔ)償系統(tǒng)。 ? 分析比較了 LDPC碼在高斯 信道與在 有 PMD模擬器的光纖 傳輸 中的糾錯性能，并進(jìn)行了數(shù)值模擬 ，結(jié)果表明 LDPC 碼對于 降低 光纖傳輸 系統(tǒng)的 誤碼率，提高 系統(tǒng) PMD