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.

[1] ETSI, “Radio broadcasting systems: Digital Audio Broadcasting to mobile, portable and fixed receivers”, European Telcommunication Standard, ETS 300-401, Feb. 1995.
[2] ETSI, “Digital Video Broadcasting: Framing structure, channel coding, and modulation for digital terrestrial television”, European Telcommunication Standard, ETS 300-401, Feb. 1995.
[3] http://www.ieee802.org/16/
[4] IEEE Std 802.16TM-2004, IEEE Standard for Local and Metropolitan Area Networks － part 16: Air Interface for Fixed Broadband Wireless Access Systems. New York: IEEE, june, 2004.
[5] IEEE Std 802.16TM-2001, IEEE Standard for Local and Metropolitan Area Networks － part 16: Air Interface for Fixed Broadband Wireless Access Systems. New York: IEEE, December, 2001.
[6] IEEE Std 802.16a-2003, IEEE Standard for Local and Metropolitan Area Networks － part 16: Air Interface for Fixed Broadband Wireless Access Systems － Amendment 2: Medium Access Control Modifications and Additional Physical Layer Specifications for 2-11GHz. New York: IEEE, April 1, 2003.
[7] IEEE Std 802.16cTM-2002, IEEE Standard for Local and Metropolitan Area Networks － part 16: Air Interface for Fixed Broadband Wireless Access Systems － Amendment 1: Detailed System Profiles for 10-66 GHz. NEW York: IEEE, December, 2002
[8] Mingqi Li, Jianguo Tan, Wenjun Zhang, “A channel estimation method based on frequency-domain pilots and time-domain processing for OFDM systems”, Consumer Electronics, IEEE Transactions on, Volume 50, Issue 4, Nov. 2004.
[9] Won-Gyu Song, Jong-Tae Lim, “Pilot-symbol aided channel estimation for OFDM with fast fading channels”, Broadcasting, IEEE Transactions on, Volume 49, Issue 4, Dec. 2003.
[10] Morelli, M., Mengali, U, A comparison of pilot-aided channel estimation methods for OFDM systems”, IEEE Transactions on, Volume 49, Issue 12, Dec. 2001.
[11] Shengli Zhou, Muquet, B., Giannakis, G.B., “Subspace-based (semi-) blind channel estimation for block precoded space-time OFDM”, IEEE Transactions on, Volume 50, Issue 5, May 2002.
[12] Necker, M.C., Stuber, G.L., “Totally blind channel estimation for OFDM on fast varying mobile radio channels”, Wireless Communications, IEEE Transactions on, Volume 3, Issue 5, Sept. 2004.
[13] Petropulu, A., Ruifeng Zhang; Lin, R., “Blind OFDM channel estimation through simple linear precoding”, Wireless Communications, IEEE Transactions on, Volume 3, Issue 2, March 2004.
[14] Simon Haykin, “Adaptive Filter Theory”, 3rd Edition, December 27, 1995.