【正文】 ach function module as well as the toplevel module, after the internal integrated into FPGA chips, such not only can solve the traditional UART chip faults and at the same time also bee more pact and the whole system reliability. This topic main design baud rate generator module, receives the start module, receiving module and sending module. In the detailed design process, with each module using verilog language programming, and through the Modelsim simulation test. Key Words： Turbo codes； SOVA algorithm； VHDL； Modelsim III 目錄 1 緒論 .............................................................................................................................. 1 Turbo 碼編譯碼器的研究目的和意義 ............................................................. 1 國內(nèi)外研究現(xiàn)狀 ............................................................................................... 2 論文的安排 ....................................................................................................... 5 2 Turbo 碼編譯碼器的原理及算法 ................................................................................ 6 Turbo 碼編碼原理 ............................................................................................. 6 交織器 ............................................................................................................... 7 規(guī)則交織器 ............................................................................................ 7 偽隨機(jī)交織器 ........................................................................................ 8 系統(tǒng)卷積碼編碼器 ......................................................................................... 10 Turbo 碼譯碼原理 ........................................................................................... 11 SISO 譯碼模塊 ..................................................................................... 11 軟判決譯碼與硬判決譯碼 .................................................................. 12 譯碼器結(jié)構(gòu) .......................................................................................... 12 SOVA 譯碼算法 ............................................................................................. 13 累積路徑度量的計算 .......................................................................... 13 計算軟判決 值 ...................................................................................... 14 軟判決值的更新 .................................................................................. 14 外部信息值 的計算 .............................................................................. 14 改進(jìn)的 SOVA 譯碼算法 ..................................................................... 14 3 編碼器的設(shè)計與實現(xiàn) ................................................................................................ 17 偽隨機(jī)序列發(fā)生器 ......................................................................................... 17 交織器 ............................................................................................................. 17 分量編碼器模塊 ............................................................................................. 32 截余模塊 ......................................................................................................... 35 幀同步機(jī) ......................................................................................................... 35 信道模型 ......................................................................................................... 36 接收機(jī)的分接插入模塊 ................................................................................. 37 IV 4 譯碼器的設(shè)計與實現(xiàn) ................................................................................................ 38 定點量化 ......................................................................................................... 38 譯碼器的實現(xiàn) ................................................................................................. 38 單譯碼器的設(shè)計 .................................................................................. 38 譯碼器總體框圖 .................................................................................. 39 SOVA 譯碼器的設(shè)計 .......................................................................... 40 反相計 算模塊工作原理 ...................................................................... 45 交織與解交織 ...................................................................................... 46 5 Turbo 碼編譯碼器的系統(tǒng)仿真 .................................................................................. 48 仿真工具 ......................................................................................................... 48 仿真語言 ......................................................................................................... 49 集成開發(fā)環(huán)境的選擇 .......................................................................... 49 設(shè)計語言的選擇 .................................................................................. 49 仿真流程 ......................................................................................................... 50 結(jié)論 .................................................................................................................................. 56 致謝 .................................................................................................................................. 57 參考文獻(xiàn) .......................................................................................................................... 58 附錄 A 英文原文 ............................................................................................................ 60 附錄 B 漢語翻譯 ............................................................................................................. 66 1 1 緒論 Turbo 碼 編譯碼器的研究目的和意義 1948 年， Shannon 發(fā)表了題為 《 A Mathematical Theory of the Communication》的著名論文，在這一論文中， Shannon 提出的理論為信息編碼以及現(xiàn)代通信理論糾錯碼的奠定了基礎(chǔ)，它的發(fā)表標(biāo)志著信息與編碼這一學(xué)科的創(chuàng)立。 目前 Turbo 碼已經(jīng)應(yīng)用在許多領(lǐng)域，例如在 CDMA 多用戶檢測技術(shù)、均衡技術(shù)等