用於數位影像廣播系統之以多重路徑干擾消除為基礎之通道等化方法的設計與模擬

Abstract

在現今的社會中，多媒體以及電腦通訊扮演著一個重要的角色。垂直正交多工（OFDM）調變具有高速資訊傳輸的能力。目前已應用在新一代的數位廣播傳輸技術，如數位音訊廣播（DAB）及數位視訊廣播之地面廣播（DVB-T）等系統中。DVB-T的系統擁有比傳統類比電視更高畫質的收視品質(HDTV、SDTV)。 本論文將介紹用於DVB-T系統的OFDM通道等化方法。在接收端利用估計的通道計算路徑的延遲，重建多重路徑的干擾。利用反覆演算的機制來改善通道等化器的效能。另外，使用通道編碼（華士碼）產生傳送資料的關連性進而增加編碼增益。以電腦模擬的方式來驗證並分析所設計之通道等化方法對於DVB-T系統性能之提升。

Nowadays, multimedia and computer communication are playing an important role. Orthogonal Frequency Division Multiplexing（OFDM）, which makes information transmitted at a high speed, has applied to the digit of new generation broadcasts transmission technology, such as the DAB system and the DVB-T system. The DVB-T system has higher quality (HDTV，SDTV) than the traditional analogue TV system. This thesis will introduce an OFDM channel equalization method which is used in the DVB-T system. Utilizing the estimated channel response in receiver to compute the path delay, the multi path interference can be reconstructed. By the implementation of iterative algorithm, it will improve the performance of the channel equalization. In addition, we can use the channel coding to produce the correlation between the transmitting data, and then possess the coding gain. The computer simulation method will verify and analyze the effect of the channel equalization method to the DVB-T system.