正交分頻多工系統在超高速移動環境下的低複雜度載波間干擾消除機制

Abstract

本論文主要討論在超高速移動環境下，正交分頻多工系統載波間干擾之問題。傳統正交分頻多工系統受到了時變通道的影響，載波能量溢出至相鄰載波，破壞了原本載波間的正交性。固有的載波消除機制，在高載波數的正交分頻多工系統中，由於其高複雜度的緣故，造成實作上的困難，故我們提出一低複雜度之機制，分別從等化端及估測端降低其複雜度，並在最後加入高速鐵路行進路徑已知的特性，利用此資訊對系統效能做進一步的改善。

My study is focus on low complexity ICI cancellation on OFDM in very high mobility environment. In conventional OFDM system, because of time-varying fading channels, subcarrier energy leak to other subcarriers. It destroys the orthogonal relation among all subcarriers in OFDM system, Conventional ICI cancellation method is difficult to be realized for its high complexity, so we proposed a low complexity ICI cancellation method. We lowered its complexity from the receiver and transmitter, and added the existed information of railroad system to improve performance of OFDM system.