臺灣博碩士論文加值系統

近年來，為了可以增加無線通信系統之資料傳輸速率以及頻譜使用效率，正交分頻多工系統結合波束形成技術的方式以被廣泛的討論。為了可以獲得最佳的系統效能，必須解決同頻干擾。使用波束形成技術是一個有效克服同頻干擾的方式。應用於正交分頻多工之波束形成技術可以分為前置-快速傅立葉轉換型以及後置-快速傅立葉轉換型兩類。本文中，分別討論前置-快速傅立葉轉換型以及後置-快速傅立葉轉換型波束形成器之優缺，並提出一個新式結合前置-快速傅立葉轉換型以及後置-快速傅立葉轉換型之波束形成器。此新式混合型波束形成器，在有同頻干擾的時變通道之下，相較於前置-快速傅立葉轉換型及後置-快速傅立葉轉換型之波束形成器可以得到較佳的系統效能。

中文摘要 Ⅰ
英文摘要 Ⅱ
致謝 Ⅲ
目錄 Ⅳ
表目錄 Ⅵ
圖目錄 Ⅶ

第一章 緒論 1
1.1 研究動機 1
1.2 研究目標 2
1.3 論文架構 3
第二章 智慧型天線系統 4
2.1 智慧型天線之基本概念 4
2.1.1 均勻間距線性陣列 5
2.1.2 空間濾波器及空間耐奎斯特取樣定理 9
2.2 智慧型天線技術 11
2.2.1 切換波束式天線陣列 11
2.2.2 適應性天線陣列 12
2.2.2.1 權重最佳化之準則 12
2.2.2.2 最小平均平方誤差準則 13
2.2.2.3 最大訊號干擾比 14
2.2.2.4 應用於波束形成之適應性演算法 16
2.2.2.5 倒置取樣矩陣演算法 17
2.2.2.6 最小平均平方演算法 18
2.2.2.7 遞迴最小平方演算法 19
2.3 智慧型天線對系統的改善及主要用途 21
第三章 正交分頻多工技術 24
3.1 正交分頻多工技術介紹 24
3.2 保護區間與載波正交性 27
3.3 正交分頻多工系統之優缺點 29
第四章 應用於正交分頻多工系統之波束形成技術 31
4.1 通道模型 31
4.2 前置-快速傅立葉轉換型天線系統 32
4.2.1 前置-快速傅立葉轉換型之結構 32
4.2.2 理想切換波束天線陣列 33
4.2.3 切換波束式天線系統 36
4.2.3.1 最大能量法 37
4.2.3.2 最大能量法模擬分析 38
4.3 後置-快速傅立葉轉換型天線陣列 40
4.3.1 後置-快速傅立葉轉換型之結構 40
4.3.1.1 倒置取樣矩陣演算法之模擬 43
4.3.1.2 子載波群組化 47
4.3.1.3 子載波波束形成器之內插 51
第五章 新式波束形成器設計 62
5.1 最小平方誤差法 62
5.1.1 頻域最小平方誤差法 62
5.1.2 時域最小平方誤差法 65
5.1.3 效能分析 66
5.1.4 複雜度分析 68
5.1.5 前置-快速傅立葉轉換型以及後置-快速傅立葉轉換型之優缺點比較 69
5.2 新式混合型天線陣列結構 71
5.2.1 效能分析 72
5.2.2 複雜度分析 78
第六章 結論與未來工作展望 79
參考文獻 81

[1] S. Bellofiore, J. Foutz, C. A. Balanis, and A. S. Spanias, “Smart-antenna system for mobile communication networks Part 2: Beamforming and network throughput,” IEEE Antenna’s and Propagation Magazine, Vol. 44, No 4, Aug. 2002.
[2] J. Litva and T. Lo, Digital Beamforming in Wireless Communications, Artech House Publishers, Massachusetts, 1996.
[3] S. Haykin, Advances in Spectrum Analysis and Array Processing, Vol. II, Prentice Hall, New Jersey, 1991.
[4] B. V. Veen and K. Buckley, “Beamforming: A versatile approach to spatial filtering,” IEEE ASSP Magazine, pp. 4-22, Apr. 1988.
[5] A. V. Oppenheim and R. W. Schafer, Discrete -Time Signal Processing, Prentice Hall, New Jersey, 1989.
[6] W. L. Stutzman and G. A. Thiele, Antenna Theory and Design, John Wiley & Sons, New York, 1981.
[7] A. Alexiou and M. Haardt, “Smart antenna technologies for future wireless systems: trends and challenges,” IEEE Communications Magazine, Sept. 2004.
[8] S. Bellofiore, C. A. Balanis, J. Foufz, and A. S. Spanias, “Smart-antenna system for mobile communication networks Part I: Overview and antenna design,” IEEE Antenna’s and Propagation Magazine, Vol. 44, No 3, Jun. 2002.
[9] I. S. Reed, J. D. Mallett and L. E. Brennan, “Rapid convergence rate in adaptive arrays,” IEEE Transactions on Aerospace and Electronic Systems, AES-10, No.6, Nov. 1974.
[10] P. S. Wijesena, T. Taniguchi and Y. Karasawa, “Adaptive algorithm based on accumulated signal processing for fast fading channels with application to OFDM mobile radio,” IEICE Trans. Commun., Vol. E88–B, No.2, Feb. 2005.
[11] Jr. R. T. Compton, Adaptive Antennas, Concept and Performance, Prentice Hall, Englewood Cliffs, New Jersey, 1988.
[12] S. Haykin, Adaptive Filter Theory, 3rd edition, Prentice Hall, New Jersey, 1996.
[13] B. Farhang-Boroujeny, Adaptive Filters Theory and Applications, Wiley, Oct. 2000.
[14] M. Chryssomallis, “Smart antennas,” IEEE Antenna’s and Propagation Magazine, Vol. 42, Issue 3, Jun. 2000.
[15] N. Herscovici, and C. Christodoulou, “Potentials of smart antennas in CDMA systems and uplink improvements,” IEEE Antenna’s and Propagation Magazine, Vol. 43, Issue 5, Oct. 2001.
[16] C. B. Dietrich, W. L. Jr., Stutzman, B. K. Kim and K. Dietze, “Smart antennas in wireless communications: base-station diversity and handset beamforming,” IEEE Antenna’s and Propagation Magazine, Vol. 42, Issue 5, Oct. 2000.
[17] G. V. Tsoulos, “Smart antennas for mobile communication systems: benefits and challenges,” Electronics & Communication Engineering Journal, Vol. 11, Issue 2, Apr. 1999.
[18] R. V. Nee and R. Prasad, OFDM for Wireless Multimedia Communications, Artech House, Jan. 2000.
[19] S. M. Lee, B. H. Yoon and H. J. Choi, “On beamforming for space-time block coded OFDM systems in multipath fading channels,” IEICE Trans. Commun., Vol. E88–B, No.3, Mar. 2005.
[20] Y. Sun and H. Matsuoka, “A novel adaptive antenna architecture subcarrier clustering for high-speed OFDM systems in presence of rich co-channel interference,” IEEE VTC’ 2002, Vol. 3, pp.1564–1568, Spr. 2002.
[21] R. B. Ertel, P. Cardieri, K. W. Sowerby, T. S. Rappaport and J. H. Reed, “Overview of spatial channel models for antenna array communication systems,” IEEE Personal Communications, Vol. 5, Issue 1, Feb. 1998.
[22] M. Budsabathon, Y. Hara and S. Hara, “Optimum beamforming for pre-FFT OFDM adaptive antenna array,” IEEE Transactions on Vehicular Technology, Vol. 53, No4, Jul. 2004.
[23] B. Liu, R. Jin and Y. Fan, “Modified pre-FFT OFDM adaptive antenna array with beam-space channel estimation,” Electronics Letters, Vol. 40, Issue 5, Mar. 2004.
[24] L. Fan, H. Zhang and C. He, “Minimum bit error rate beamforming for pre-FFT OFDM adaptive antenna array,” VTC-2005-Fall. 2005 IEEE 62nd.
[25] Z. Zhang, M.F. Iskander, Z. Yun and A. Host-Madsen, “Hybrid smart antenna system using directional elements - performance analysis in flat Rayleigh fading,” IEEE Transactions on Antennas and Propagation, Vol. 51, No. 10, Oct. 2003.
[26] P. Ngamjanyaporn, C. Phongcharoenpanich, P. Akkaraekthalin and M. Krairiksh, “Signal-to-interference ratio improvement by using a phased array antenna of switched-beam elements,” IEEE Transactions on Antennas and Propagation, Vol. 53, No. 5, May 2006.
[27] S. H. Chu, H. P. Lin and D. B. Lin, “Performance enhancement by using switch-beam smart antenna in 802.11a WLAN system,” Wireless Communications and Applied Computational Electromagnetics, 2005. IEEE/ACES International Conference on 3-7 Apr. 2005.
[28] J. Butler and R. Lowe, “Beamforming matrix simplifies design of electronically scanned antennas,” Electronic Design, Apr. 1961.
[29] Z. Lei and F. P. S. Chin, “Post and pre-FFT beamforming in an OFDM System,” VTC-2004-Spring. 2004 IEEE 59th.
[30] Y. Sun and H. Matsuoka, “A novel adaptive antenna architecture - subcarrier clustering for high-speed OFDM systems in presence of rich co-channel interference,” VTC-2002-Spring. IEEE 55th.
[31] M.-H. Lai, “Clock synchronization of VDSL system,” M.S. thesis, Institute of Electronics, National Chiao Tung University, Hsin-Chu, Taiwan, May 2004.
[32] K.G. Seog and H. M. Yong, “A comparative investigation on channel estimation algorithm for OFDM in mobile communications,” IEEE Trans., Vol. 49, No.2, Jun. 2003.