Responsive image
博碩士論文 etd-0114110-171220 詳細資訊
Title page for etd-0114110-171220
論文名稱
Title
正交分頻多工系統之通道估測研究
A Study on Channel Estimation of OFDM Systems
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
44
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2009-07-21
繳交日期
Date of Submission
2010-01-14
關鍵字
Keywords
共軛對稱、實數訊號、通道估測、空載波
diversity, OFDM
統計
Statistics
本論文已被瀏覽 5650 次,被下載 0
The thesis/dissertation has been browsed 5650 times, has been downloaded 0 times.
中文摘要
在此篇論文中,我們提出了一種應用於OFDM系統中的盲蔽式通道估測演算法。在此我們利用了OFDM系統中訊號在頻域共軛對稱之特性,使在時域中產生實數訊號,並且利用這些實數訊號來建構出雜訊空間。將我們的方法與傳統利用空載波的方法比較之後,傳統方法需要較多的OFDM符號數目才能夠得到較好的效能。除此之外,傳統方法的運算複雜度會比我們的方法來的高。雖然我們所提出的方法具有上述之優點,但由於利用了共軛對稱的特性來產生實數訊號,因此我們勢必會損失一半的資料傳輸量。從模擬結果來看,在相同資料量的情況下,我們提出的方法可以比傳統的加入空載波的方法具有更好的效能。
Abstract
A blind channel estimation based on subspace method for orthogonal frequency division multiplexing (OFDM) systems is proposed in this thesis. Conjugate symmetric property of the OFDM symbols in the frequency-domain, which will result real time-domain symbol, is used in the proposed method to build the noise subspace. When the performance of the proposed method is compared with that of conventional method using virtual carriers, more OFDM symbols are needed in the conventional method than those needed in the proposed method. In addition, the computational complexity of the conventional method is also larger than that of the proposed method. Although the proposed method has better performance and less computational complexity compared with the conventional method, it would lose half of the transmission data rate. From the simulation results, our proposed method outperforms the conventional method.
目次 Table of Contents
誌謝……………………………………………………………………………………i
摘要……………………………………………………………………………………ii
Abstract iii
目錄 iv
圖索引 vi
表目錄 viii
第一章 簡介 1
1.1研究背景 1
1.2各章簡介 2
第二章 OFDM相關概念 3
2.1OFDM簡介 3
2.2 OFDM基本架構 4
2.3 Guard Interval簡介 6
2.3.1保護區間 6
2.3.2循環字首與循環字尾 7
2.4 通道估測 10
2.4.1半盲蔽式通道估測法 11
2.4.2盲蔽式通道估測法 13
2.4.3指標符號排列與設計方式 13
第三章 利用實數訊號之子空間式通道估測演算法 16
3.1 傳統方式 16
3.2 利用實數訊號建構雜訊空間之方法 19
3.3 將複數傳送訊號轉換成實數訊號的形式 20
第四章 系統模擬結果 22
4.1在不同OFDM符號個數下與傳統方式的比較 22
4.2 加入diversity 26
4.3 演算法複雜度之分析 30
第五章 結論 33
參考文獻 34
參考文獻 References
[1] T. Cui and C. Tellambura,“Semiblind channel estimation and data detection for OFDM systems with optimal pilot design,”IEEE Trans. Commun., vol. 55, no. 5, pp. 1053-1062, May 2007.
[2] T. Cui and C. Tellambura,“Blind receiver design for OFDM systems over doubly selective channels,”IEEE Trans. Commun., vol. 55, no. 5 , pp. 906-917, May 2007.
[3] S. Roy and C. Li,“A subspace blind channel estimation method for OFDM systems without cyclic prefix,”IEEE Trans. Wireless Commun., vol. 1, no. 4, pp. 572-579, Oct. 2002.
[4] C. Li and S. Roy,“Subspace-based blind channel estimation for OFDM by exploiting virtual carriers,”IEEE Trans. Wireless Commun., vol. 2, no. 1, pp. 141-150, Jan. 2003.
[5] H. Wang, Y. Lin, and B. Chen,“Data-efficient blind OFDM channel estimation using receiver diversity,”IEEE Trans. Signal Pro., vol. 51, no. 10, pp. 2613-2623, Oct. 2003.
[6] T. Cui and C. Tellambura,“Joint frequency offset and channel estimation for OFDM systems using pilot symbols and virtual carriers,”IEEE Trans. Wireless Commun., vol. 6, no. 4, pp. 1193-1202, Apr. 2007.
[7] F. Gao, A. Nallanathan, and C. Tellambura,“Blind channel estimation for cyclic-prefixed single-carrier systems by exploiting real symbol characteristics,”IEEE Trans. Veh. Technol., vol. 56, no. 5, pp. 2487-2498, Sep. 2007.
[8] B. Su and P. P. Vaiydanathan,“Subspace-based blind channel identification for cyclic prefix systems using few received blocks,”IEEE Trans. Signal Pro., vol. 55, no. 10, pp. 4979-4993, Oct. 2007.
[9] X. Dong., W.-S. Lu, and A. C. K.,“Linear interpolation in pilot symbol assisted channel estimation for OFDM,”IEEE Trans. Wireless Commun., vol. 6, no. 5, pp. 1910-1920, May 2007.
[10] Y.-S. Lee, H.-N. Kim, S. I. Park, and S. I. Lee,“Noise reduction for channel estimation based on pilot-block averaging in DVB-T receivers,”IEEE Trans. Consum. 58 Electro., vol. 52, no. 1, pp. 51-58, Feb. 2006.
[11] J. G.. Proakis, Digital Communications, 4th ed. New York:McGraw-Hill, 2001.
[12] J.-J. van de Beek, O. Edfors, M. Sandell, S. K. Wilson, and P. O. Bojesson,“On channel estimation in OFDM systems,”in Proc. IEEE Veh. Technol. Conf., vol. 2, Chicago, IL, pp. 815 – 819, July 1995.
[13] O. Edfors, M. Sandell, J.-J. van de Beek, S. K. Wilson, and P. O. Bojesson,“OFDM channel estimation by singular value decomposition,”IEEE Trans. Commun., vol. 46, pp. 931-939, July 1998.
[14] W. G.. Jeon, K. H. Paik, and Y. S. Cho,“An efficient channel estimation technique for OFDM systems with transmitter diversity,”IEICE Trans. Commun., vol. E84-B, no. 4, pp. 967-974, Apr. 2001.
[15] J.-H. Lee and S.-C. Kim,“Efficient ISI cancellation for STBC OFDM systems using successive interference cancellation,”IEEE Commun. Letters, vol. 10, no. 8, pp. 629-637, Aug. 2006.
[16] C.-Z. Zhan, K.-Y. Jheng, Y.-L. Chen, T.-J. Jheng and A.-Y. Wu,“High-convergence-speed low-computation-complexity SVD algorithm for MIMO-OFDM systems,”in Proc. IEEE Int. Symp. VLSI Design, Automation, and Test (VLSI-DAT-2009), Hsinchu, Taiwan, pp. 195-198, Apr., 2009.
電子全文 Fulltext
本電子全文僅授權使用者為學術研究之目的,進行個人非營利性質之檢索、閱讀、列印。請遵守中華民國著作權法之相關規定,切勿任意重製、散佈、改作、轉貼、播送,以免觸法。
論文使用權限 Thesis access permission:校內校外均不公開 not available
開放時間 Available:
校內 Campus:永不公開 not available
校外 Off-campus:永不公開 not available

您的 IP(校外) 位址是 54.221.69.42
論文開放下載的時間是 校外不公開

Your IP address is 54.221.69.42
This thesis will be available to you on Indicate off-campus access is not available.

紙本論文 Printed copies
紙本論文的公開資訊在102學年度以後相對較為完整。如果需要查詢101學年度以前的紙本論文公開資訊,請聯繫圖資處紙本論文服務櫃台。如有不便之處敬請見諒。
開放時間 available 已公開 available

QR Code