A Second Order log-MAP Algorithm for Turbo Code Decoding in CDMA Communications under Fading
蔡鳴凱、潘天賜
E-mail: 9607746@mail.dyu.edu.tw
ABSTRACT
A novel log-MAP algorithm with second order approximation for turbo code decoding in CDMA communications under fading is presented. Simulation results are performed for the IS-2000 CDMA turbo code under Additive White Gaussian Noise (AWGN) and slow fading channels by using various log-MAP algorithms. Results reveal that bit-error-rate (BER) performance of proposed second order log-MAP algorithm is superior to those of previous log-MAP algorithms such as max-log-MAP, constant-log-MAP, and linear-log-MAP.
Keywords : Code Division Multiple Access ; Turbo Decoding
Table of Contents
封面內頁 簽名頁 授權書．．．．．．．．．．．．．．．．．．．． iii 中文摘要．．．．．．．．．．．．．．．．．
．． iv 英文摘要．．．．．．．．．．．．．．．．．．． v 誌謝．．．．．．．．．．．．．．．．．．．．． vi 目 錄．．．．．．．．．．．．．．．．．．．．． vii 圖目錄．．．．．．．．．．．．．．．．．．．． ix 第一章 緒 論 ．．．．．．．．．．．．．．．．．1 1.1 研究動機與目的 ．．．．．．．．．．．．．．1 1.2 論文架構 ．．．．．
．．．．．．．．．．．．2 第二章 文獻探討 ．．．．．．．．．．．．．．．3 2.1 數位通訊理論 ．．．．．．．．
．．．．．．．3 2.2 錯誤控制碼（Error Control Coding） ．．．．4 2.2.1 區塊碼（Block Code）．．．．．．．．．． 4 2.2.1.1 漢明碼（Hamming Code）．．．．．． 5 2.2.1.2 BCH碼．．．．．．．．．．．．．．．7 2.2.2 迴旋碼
（Convolutional Code）．．．．．． 9 2.2.3 Viterbi迴旋解碼演算法則．．．．．．．．．13 2.3 低密度奇偶檢查碼
（LDPC）．．．．．．．．． 16 2.4 多重擷取技術．．．．．．．．．．．．．．． 17 2.4.1 FDMA．．．．．．．．
．．．．．．．．．． 17 2.4.2 TDMA．．．．．．．．．．．．．．．．．． 18 2.4.3 CDMA．．．．．．．．．．．
．．．．．．． 19 2.5 Shannon通道資訊容量 ．．．．．．．．．．． 21 2.6 加成性白色高斯雜訊（AWGN） ．．．．．
．．．22 2.7 雷萊衰減（Rayleigh fading）．．．．．．．．24 第三章 渦輪碼原理．．．．．．．．．．．．．． 26 3.1 渦輪碼編碼器（Turbo Code Encoder）．．．． 27 3.2 遞迴系統化迴旋碼編碼器（RSC Encoder）．．．28 3.3 交錯器
（Interleaver）．．．．．．．．．．．29 3.4 渦輪碼解碼器（Turbo Code Decoder）．．．． 30 3.5 渦輪碼解碼演算法．
．．．．．．．．．．．． 31 第四章 二階log-MAP渦輪解碼演算法 ．．．．．．43 第五章 研究結果．．．．．．
．．．．．．．．． 46 第六章 結論．．．．．．．．．．．．．．．．． 49 參考文獻．．．．．．．．．．．．．．
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