【正文】 畢業(yè)設(shè)計(jì)（論文） 摘要 在數(shù)字通信系統(tǒng)中，通常采用差錯(cuò)控制編碼來(lái)提高系統(tǒng)的可靠性。自 P． Elias首次提出卷積碼編碼以來(lái)，這一編碼技術(shù)至今仍顯示出強(qiáng)大的生命力。目前，卷積碼已廣泛應(yīng)用在無(wú)線通信標(biāo)準(zhǔn)中，如 GSM， CDMA20xx 和 IS95 等無(wú)線通信標(biāo)準(zhǔn)中。 針對(duì) NCDMA 數(shù)據(jù)傳輸過(guò)程中的誤碼問題 ,本文論述了旨在提高數(shù)據(jù)傳輸質(zhì)量的維特比譯碼器的設(shè)計(jì)。 雖然 Viterbi 譯碼復(fù)雜度較大，實(shí)現(xiàn)較為困難，但效率高，速度快。 因此本文著重分析和討論了 1/2 速率的（ 2,1,9）卷積碼編碼和其 Viterbi 譯碼算法。深入研究卷積碼編碼原理 和 Viterbi 算法原理后，提出了（ 2,1,9）卷積碼編碼以及 Viterbi 算法的初始化、加 — 比 — 選和回溯 設(shè)計(jì) 方案， 運(yùn)用查表的方法 ,避免了大量繁瑣計(jì)算 ,使得譯碼簡(jiǎn)潔迅速 ,譯碼器的實(shí)時(shí)性能良好。并充分利用TMS320C54X 系列 DSP 芯片 ，用匯編語(yǔ)言完成了（ 2,1,9）卷積碼編碼和 Viterbi譯碼的程序。 關(guān)鍵詞：差錯(cuò)控制編碼、卷積碼、 Viterbi 譯碼、 TMS320C54X、 DSP 畢業(yè)設(shè)計(jì)（論文） Abstract In digital munication systems, error control coding is usually used to improve system reliability. Since put forward the convolutional coding the first time, the coding is still showing strong vitality.,has bee widely used in satellite munications, wireless munications and many other munication systemsas a kind of channel coding method. such as GSM, CDMA20xx and has been a wireless munication standards of IS95. In view of the error problem in the process of NCDMA data transmission, this paper discusses the aims to improve the quality of data transmission of victor design than the decoder. Although Viterbi decoding plexity is bigger, more difficult to achieve, but high efficiency and fast speed. So this article emphatically analyzed and discussed the 1/2 rate (2,1,9) convolution code coding and its Viterbi decoding algorithm. Indepth study on principle of convolution code coding and Viterbi algorithm, proposed the convolution code coding and Viterbi algorithm (2,1,9) initialization, add than choose and back design, using lookup table method, to avoid a large amount of tedious calculation, the decoding and quick, good realtime performance of the decoder. Make full use of the series of TMS320C54X DSP chip, using assembly language to plete the（ 2,1,9） convolution code coding and Viterbi decoding process. Keywords: error control coding, convolutional code, Viterbi decoding, TMS320C54X 畢業(yè)設(shè)計(jì)（論文） 目錄 摘要 ........................................................................................................................ 1 Abstract .................................................................................................................. 2 目錄 ........................................................................................................................ 3 ..................................................................................................................... 1 移動(dòng)通信及 NCDMA 背景 .................................................................... 1 數(shù)字通信概述 ......................................................................................... 1 卷積編碼與譯碼的發(fā)展 ......................................................................... 3 主要研究工作 ......................................................................................... 3 與 CCS 簡(jiǎn)介 ................................................................................................. 5 DSP 概述 .................................................................................................. 5 DSP 的主要特點(diǎn) ........................................................................... 5 CSSU 單元概述 ............................................................................. 7 CCS 概述 ................................................................................................... 8 本章小結(jié) ................................................................................................. 8 ............................................................................................. 9 卷積碼的概述 ......................................................................................... 9 卷積碼基本原理 .......................................................................... 9 卷積碼的糾錯(cuò)能力 ...................................................................... 9 卷積碼的表示方法 .................................................................... 10 Viterbi 譯碼的概述 ............................................................................ 11 本章小結(jié) ............................................................................................... 14 4． 卷積編碼的實(shí)現(xiàn) .......................................................................................... 15 (2,1,9)卷積碼編碼 .............................................................................. 15 (2,1,9)卷積碼編碼設(shè)計(jì)方案 ................................................... 15 (2,1,9)卷積碼編碼流程圖 ....................................................... 16 (2,1,9)卷積編碼程序?qū)崿F(xiàn) ....................................................... 16 (2,1,9)的程序仿真 ................................................................... 17 (2,1,9)卷積碼狀態(tài)轉(zhuǎn)換表 .................................................................. 17 (2,1,9)卷積碼狀態(tài)轉(zhuǎn)換表的設(shè)計(jì)算法 ................................... 18 (2,1,9)卷積碼狀態(tài)轉(zhuǎn)換表的流程圖 ....................................... 18 (2,1,9)卷積碼狀態(tài)表 ............................................................... 19 (2,1,9)卷積碼狀態(tài)表的蝶形結(jié)構(gòu) ........................................... 21 本章小結(jié) ............................................................................................... 22 5. Viterbi 譯碼的實(shí)現(xiàn) .......................................................................................... 23 Viterbi 譯碼基礎(chǔ) ................................................................................... 23 Viterbi 譯碼算法 ................................................................................... 23 變量定義情況 ....................................................................................... 25 畢業(yè)設(shè)計(jì)（論文） 初始化 ................................................................................................... 26 初始化流程圖 ............................................................................ 27 初始化程序仿真 ........................................................................ 27