本論文中，我們探討正交分頻多工系統經過加成性高斯白雜訊通道下遇到脈衝雜訊(impulsive noise)對系統之影響，對此我們使用了非線性消除(Blanking nonlinearity)的方法來消除脈衝雜訊。此方法已經被廣泛應用於實際的正交分頻多工系統，以用來抑制通道傳送時所產生的脈衝雜訊，雖然非線性消除可以成功抑制脈衝雜訊但卻會造成通道載波間的相互干擾(intercarrier interference , ICI)，為了提高訊號傳送的性能，本篇論文提出了疊代干擾消除(iterative interference cancellation )的方法，來有效的抑制脈衝雜訊與減少載波間的相互干擾。
　　本篇論文模擬隨著改變疊代次數、載波點數、信號對噪音比以及信號對脈衝雜訊比，來觀察改變系統參數與通道環境對接收機效能之影響。

In this thesis, the orthogonal frequency division multiple (OFDM) signals with blanking nonlinearity in impulsive noise channels is presented. Blanking nonlinearity has been widely used in practical OFDM systems to suppress impulsive noise at the expense of reducing signal power and generating intercarrier interference (ICI).
　　To improve the performance of blanking nonlinearity element, we propose an iterative interference cancellation scheme which can effectively reduce the level of ICI caused by the blanking operation at the OFDM receiver. With adaptive blanking threshold for each iteration, the proposed iterative receiver design can converge to its best performance with only three iterations.
    Simulation results achieved by the proposed scheme significant improvement.

目錄
致謝                             I
中文摘要                           III
英文摘要                           IV
目錄                            VI
圖目錄                            VIII
第一章　緒論                         1
    1.1研究背景                       1
    1.2研究目的與方法                    4
    1.3論文架構                       6
第二章　知識背景                       7
   2.1正交分頻多工系統                    7
   2.2 加成性高斯白雜訊                   17
   2.3 脈衝雜訊                       20
第三章　非線性消隱運算與疊代消除干擾             24
   3.1 脈衝雜訊消除                     24
　　  3.1.1 非線性節波法                  24
　　  3.1.2 非線性消隱法                  25
　　  3.1.3 Sergey V. Zhidkov 提出之消除脈衝雜訊演算法  26
　　  3.1.4 本論文使用的脈衝雜訊消除方法          28
   3.2 疊代子載波消除干擾                  31
第四章　實驗結果                       38
第五章　結論                         51
參考文獻                           52

圖目錄
圖1.1 利用保護區間消除符元間干擾               2
圖2.1 OFDM與FDM頻譜比較                   8
圖2.2 正交分頻多工系統發射端架構圖             11
圖2-3 連續時間正交分頻多工調變示意圖            12
圖2.4 連續時間正交分頻多工系統解調示意圖          13
圖2.5 離散時間正交分頻調變解調示意圖            14
圖2.6 完整的正交分頻多工系統符號              15
圖2.7(a) 加入循環字首的正交分頻多工符號           16
圖2.7(b) 通道延遲下接收端在T_F區間內仍可取得整數個週期的各子載波                              16
圖2.8 功率頻譜密度函數                   18
圖3.1 非線性節波消除脈衝雜訊的系統架構圖          24
圖3.2 非線性截波運算示意圖                 25
圖3.3 非線性消隱消除脈衝雜訊的系統架構圖          25
圖3.4 Sergey V. Zhidkov 提出之消除脈衝雜訊方塊圖     26
圖3.5 正交分頻多工系統架構圖                28
圖3.6 非線性消隱運算示意圖                 30
圖4.1 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         39
圖4.2 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         40
圖4.3 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         42
圖4.4 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         43
圖4.5 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         44
圖4.6 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         45
圖4.7 OFDM使用16-QAM調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                        47
圖4.8 OFDM使用16-QAM調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                        48
圖4.9 OFDM使用QPSK調變經過非線性消隱與疊代干擾消除運算後的符元錯誤率效能圖                         49

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