猛禽碼(Raptor code)可提供良好的錯誤更正能力及編解碼效率。它的噴泉碼(fountain code)特性 可有效地避免單播及群播服務的封包重傳工作。因此，有許多無線及有線寬頻的應用採用它，例 如：行動多媒體廣播系統及寬頻IPTV系統。但對串流服務來說，為了提升保護區間(protection period)長度出或是提升串流伺服器的支援頻道數效提高猛禽碼的編碼效率仍是必要的。在本論文 中，我們提出了一種針對已知固定區塊長度的高效率系統化猛禽碼編碼方法，其運作以運算序列 (operation list)為基礎。對於會使用一到數個固定區塊長度的猛禽碼應用來說我我們可以預先產生 相對應的運算序列，並使用它們來更有效率地產生編碼符號。我們首先介紹我們所提出的猛禽碼 編碼器的基本架構可接著描述產生運算序列以及猛禽碼中間符號(intermediate symbol)的細節。模 擬結果顯示我們所提出的編碼器，至少比3GPP及DVB-H標準所建議的傳統猛禽碼編碼器的運 算速度快兩倍。

Raptor code can provide good error correction capability and efficient encoding and decoding performance. Its fountain code property is effective in avoiding packet retransmission for both unicast and multicast service delivery. Hence, there are many wireless and broadband applications ad opting it such as mobile multimedia broadcasting and broadband IPTV systems. However, for streaming services, to increase the performance of Raptor code encoding is still necessary in order to support a longer protection period or to increase tha 门口阳匕 er of channels supported by a strsaming server. In this paper, we present an effi cient systematic Raptor code encoder based on operation lists for known block lengths. For a Raptor code application that can frequently use one or several fixed block 丨engths (i.e., the number of source symbols in a aoorce block), we could produce the corresponding operation lists in advance and use them to generate the encoding symbols more efficiently.We first introduce theb3sic architecture of the proposed Raptor encoder, and then describe the details about how to generate operation lists and Raptor intermediate symbols.The results show that our encoder is at least two times fas ter than the conventional Raptor code encoder which is adopted by 3GPP and DVB-H.