臺灣博碩士論文加值系統

為了有效地利用通道資源，能被廣泛應用的非均等錯誤保護 (unequal error protection) 近年來是一個非常熱門的研究主題，因為非均等錯誤保護能被簡單地使用於許多實際上的編碼結構，並且能使我們在信號品質及通道資源之間取得一個平衡點，所以使通道資源能被作最有效率的應用。在這篇論文之中，我們首先介紹這兩種能夠應用於非均等錯誤保護的迴旋碼：路徑刪除迴旋碼 (path-pruning convolutional code)與位元截取迴旋碼 (puncturing convolutional code) ，然後我們結合這兩種技巧來研究所產生新的碼字的性質。為了結合前述的兩種技巧，我們經常使用碼字群組化 (code blocking) 的方法。我們採用(n,1) 碼作為原始碼，然後利用適當的碼字群組化，刪除特定的碼字位元及減少真正的輸入數目，即得到結合路徑刪除及位元截取技巧的碼字，並且經由詳細地分析及證明，得到這種新的碼字的一些有用的性質。我們利用所得到的性質，並且經由碼字搜尋 (code search) ，我們得到了許多族 (family) 的碼字，它們都能使用同一個解碼器 (decoder) 解碼，所以能夠提供許多選擇於應用在非均等錯誤保護並且降低了解碼的複雜度。最後我們列出了許多碼字表，第一種碼字表是對一些最佳的路徑刪除碼作不同程度的位元截取而產生，第二種碼字表是對一些最佳的迴旋碼作不同程度的碼字群組化、路徑刪除及位元截取而產生，而由同一個原始碼所產生的所有碼字都能使用同一個解碼器解碼。

1.Introduction 1
2.Convoluitonal Codes for UEP 3
3.Combined Path-Pruned and Punctured Convolutional Codes 21
4.Code Search 32
5.Conclusion 55

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