本論文是對IEEE 802.16-2004的系統上,在通道估測技術上做一探討。而此IEEE 80216-2004是使用正交分頻多工(Orthogonal Frequency Division Multiple, OFDM)的工作模式。 而在通道估測技術上,本篇論文中使用線性預編碼的演算法在做通道估測用,其方法系在發射端做IDFT訊號處理之前,加上一線性預編碼的方塊圖,而在接收端做完DFT訊號處理之後,對訊號對自相關運算,我們即可用此自相關函式來估測出通道的參數。而接下來,我們將提出此一演算法的改進-決策回授式線性預編碼的演算法,並使用重複運算的方式來進行通道估測,最後我們將此兩種演算法在浮點運算及定點運算下做模擬與分析比較 This thesis takes a discussion on channel estimation technique in Orthogonal Frequency division Multiple (OFDM) mode of IEEE 802.16-2004 standard. Based on channel estimation, the linear precoding technique has been adopted. The linear precoding algorithms pre-process the signals before IDFT in transmitter, and the correlation computation of signals after DFT in receiver are required to estimate the parameters of the channel. Following, the decision feedback linear precoding algorithm is proposed which improves the performance by iterative approach. Following, the comparisons between conventional linear precoding algorithm and the improved linear precoding algorithm that we proposed earlier have been analyzed and simulation in floating-point and fixed-point respectively. Finally, we simulation the channel estimation algorithm in floating point and fixed point cases.