OFDM 傳輸系統中窄頻雜訊的消除技術

Abstract

本篇論文提出了一種用來抑制在CDMA-OFDM傳輸系統下窄頻雜訊的新方法( DTE).另外,也討論另一種的演算法(OTTE)來說明及比較抑制的方法和成 果.這兩種抑制法都利用到了窄頻雜訊在頻譜上所具有獨特的波形特性來 偵測出干擾並加以消除,而且都對穩定及非穩定的干擾有良好的抑制效果. 本論文所提出的DTE抑制法除了在抑制效果上和OTTE抑制法不相上下之外, DTE所需要的計算量也比OTTE要來得少.因此OTE抑制法是一個可行且簡單 的抑制窄頻雜訊的方法. The purpose of this thesis is to present a novel methodcalled "differential threshold exciser (DTE)" to suppressnarrow band interference in CDMA-OFDM transmission system.Also,another threshold exciser , "over-through threshold exciser (OTTE)",is discussed. The two methods use differenttransform characteristics of the interference and information signal to suppress the narrow band interferenceno matter the interference is stationary or nonstationary.The DTE algorithm has nearly the same performance with the OTTE algorithm with less computation complexity than the simple OTTE algorithm. Thus,the DTE algorithm is a simpleand feasible method to achieve its goal.