WiMAX主要是針對移動式用戶，目前並無公認的WiMAX無線通道模型，也沒有符合WiMAX模擬與測試的通道環境分析與通道仿真儀器；為了做一個可供使用者模擬與測試通道仿真儀器，本論文所選擇的無線通道必須適用於移動式寬頻無線通訊系統；本論文主要針對移動式的多重路徑通道衰減(Multipath Fading)做軟體模擬與FPGA實現，首先選擇IEEE組織所認可的SUI model和WCDMA的3GPP model加上適合移動式的Jakes’Model來組成適合WiMAX的多重路徑通道衰減(Multipath Fading)；再加上其他的通道效應如: 頻率偏移(Frequency Offset)、路徑損失(Path Loss)、白色高斯雜訊(AWGN)等。將以上效應做成GUI介面的模擬，除了可提供使用者自行輸入參數的功能外，並提供模組化可供硬體設計測試的測試模式，使硬體設計可針對單一的模組做測試，讓使用者可以選擇觀察某單一通道效應與綜合通道效應的特性，並對通道的模擬結果做詳細的討論與說明。
根據軟體模擬的方法與結果用Xilinx的ISE與ModelSim設計各個模組元件，並對各個模組元件與其內部子元件做測試；硬體設計同樣能提供使用者自行輸入參數的功能，讓使用者可以選擇觀察某單一通道效應與綜合通道效應的特性；最後將個別實現完成的模組與子元件組合成一個通道仿真器，用Xilinx的Active HDL包成可供Matlab Simulink測試的元件，放到Simulink裡面做訊號處理與觀察。最後針對合成硬體的工作頻率、晶片面積、加/乘法器個數作檢討與提供改進的方向。

The WiMAX communication system is mainly aimed at mobile users and has attracted popular attentions nowadays. In developing WiMAX related lab researches and products, a suitable channel emulator is indispensable. However, such equipments are rarely available. In the thesis, we are mainly aimed at the design and implementation of a wireless channel emulator suitable for WiMAX which can simulate the multipath fading effect in wireless channel. We choose the SUI model for 802.16d, 3GPP model for WCDMA, and Jakes’Model to simulate and implement the multipath fading effects of WiMAX. Besides, other channel effects such as frequency offset, path loss, AWGN, … etc., are also added to our WiMAX channel emulator.
We first create a Graphical User Interface (GUI)-based software channel simulator before actually designing the channel emulator hardware. The GUI provides users with a convenient manual parameters input which allows users to choose/modify every environment parameters during the simulation process. The software channel simulator also provides detail insights of each module of the channel emulator to help emulator hardware design. It can also provide a convenient test bench in developing the channel emulator hardware. Full modularized system simulation let users observe the result of certain channel effect or the result of comprehensive channel effect. The simulation results and corresponding physical meanings can be easily displayed via the GUI simulation.
According to the modularized simulation, we use Xilinx ISE and ModelSim to design and implement the channel emulator hardware. First, we implement and test each submodule, and then we assemble them into the channel emulator. Finally, the whole system is tested by Xilinx Active HDL and Matlab simulink. The test results of the channel emulator are compared with software simulation results to validate our hardware design. Finally, the synthesized working frequency, area and the numbers of multiplier used in our implemented channel emulator are discussed.

[1]W.C. Jakes (ed.), Microwave Mobile Communications, Wiley, New York(1974).
[2]T A Wilkinson, channel model and link simulation studies for the DECT test bed program, The University of Leeds,UK,1999
[3]Juan. J.Olmos, Design and implementation of a wideband Real-time mobile channel emulator, IEEE TRANSACTION ON VEHICULAR TECHNOLOGY , Vol.48, no. 3, MAY1999
[4]J.D.Parsons, The Mobile Radio Propagation Channel ,Halsted Press, New York(1992)
[5]R. Steele(ed.),Mobile Ratio Communication , Pentech Press, London(1994).
[6]J.G..Proakis ,Digital Communications , McGraw-Hill, New York(1993)
[7]B. Sklar, Rayleigh fading channels in mobile ratio communication, Parts І and П, IEEE Commun. Mag.(1997)
[8]W.Y.C.Lee, Mobile Cellular Communications, McGraw-Hill, New York(1989)
[9]T. S. Rappaport, Wireless Communication, Prentice-Hall, Upper Saddle River, New Jersey(1996)
[10]P.A. Bello, Characterization of randomly time-variant linear channels ,IEEE Trans. Commun.Syst. CS-11
[11]B. Glance and L. J. Greenstein, Frequency-selective fading effects in digital mobile radio with diversity combining, IEEE Trans. Commun.. COM-31
[12]R. H. Clarke, A statistical theory of mobile radio reception, Bell Syst. Tech. J. 47(1968)
[13]H. L. Van Trees , Detection, Estimation and Modulation Theory, Part 3, Wiley, New York(1968)
[14]COST-231, Urban Transmission Loss Models for Mobile Radio in the 900 MHz and 1800MHz Bands (rev. 2),COST 231 TD(90),199 Rev. 2,Den Haag(1991).
[15]V. Erceg et. al, An empirically based path loss model for wireless channels in suburban environment , IEEE JSAC,vol.17,no. 7,July 1999, pp. 1205-1211.
[16]Guanbin Xing, Manyuan Shen and Hui Liu, Frequency offset and IQ imbalance compensation for OFDM Direct-conversion receivers, University of Washington, 2001
[17]Michel C.Jeruchim, Philip Balaban, K.Sam Shanmugan, Simulation of Communication Systems Second Edition/Modeling ,Methodology and Techniques ,Kluwer Academic/Plenum Publishers, New York
[18]IEEE 802.16.3, Channel Models for Fixed Wirelsee
[19]3GPP TSG RAN, Base Station (BS) radio transmission and reception (FDD) (Release 6) ,TS 25 104 v6.6.0, June 2004.
[20] 3GPP TSG RAN, User Equipment (UE) radio transmission and reception (FDD) (Release 5), TS 25 101 v5.11.0, June 2004.
[21]Yunxin Li, and Xiaojing Huang, The Simulation of Independent Rayleigh Faders, IEEE Transactions on Communications, Vol.50, No.9, September 2002
[22]Yahong Rosa Zheng and Chengshan Xiao, Simulation Models With Correct Statistical Properties for Rayleigh Fading Channels, IEEE Transactions on Communications, Vol.51, No.6, June 2003
[23]Chengshan Xiao, Yahong R.Zheng, Improved Models for the Generation of Multiple Uncorrelated Rayleigh Fading Waveforms, IEEE Communications Letters, Vol.6, No.6, June 2002
[24] Prof. Jenming Wu , Communication System on Chip, course of NTHU.
[25] Box-Muller Transform, http://mathworld.wolfram.com/
[26]S. A. Frechtel, IEEE A novel approach to modeling and efficient simulation of frequency-selective fading radio channels,J. Select. Areas Commun. 11(3),(1993)
[27]清華大學積體電路設計中心，寬頻行動通訊系統整合技術發展三年計畫，經濟部93-95 年度科專計畫九十三年度委託學研機構研究計畫書
[28]邱熙中，符合802.16標準之通道模擬器之研製，國立清華大學碩士論文
[29]Seiichi Sampei, Applications of Digital Wireless Technologies to Global Wireless Communications, Prentice Hall , 1997.