在單載波頻域等化器通訊系統中，在傳送端與接收端有較高的相 對移動速度情況下，多路徑通道會随著每一個取樣點而改變，於是會降低子載波間的正交性，在接收端的等化器會因子載波間干擾造成效能降低。為了消除子載波間干擾效應，在本篇論文中我們提出了一個可以利用決策訊號回授疊代系統，搭配決策迴授子載波間干擾消除等化器來消除子載波間的干擾。又由於估計出越精確的通道脈衝響應能使決策迴授子載波間干擾消除等化器達到越好的效果，所以我們使用了延展型卡爾曼濾波器與非察覺型卡爾曼濾波器來追蹤通道脈衝響應。最後的模擬結果顯示我們提出的方法在行動單載波頻域等化器通訊系統中能有效的消除子載波間干擾的效應。In a single-carrier frequency domain equalizer (SC-FDE) system, the time-varying multipath channel can destroy the orthogonality among the subcarriers as the transmitter and the receiver have high relative speed. The intercarrier interference (ICI) phenomenon leads to severe performance degradation. To eliminate the effect of ICI, we propose an iterative decision feedback ICI cancellation equalizer (DFIC) in combination with a decision feedback channel estimation scheme. Since the accurate estimate of the channel impulse response (CIR) can achieve better performance of the DFIC, we consider the extended Kalman filter and the unscented Kalman Filter to estimate the CIR from the nonlinear channel model. Simulation results show that the proposed algorithm can effectively reduce the ICI effect and improve the performance of the SC-FDE system in a time-varying channel.
