正交多載波分頻多工系統
通道估測技術之研究通道估測技術之研究

以作者查詢圖書館館藏

、以作者查詢臺灣博碩士

、以作者查詢全國書目

、勘誤回報

、線上人數：38

、訪客IP：18.118.144.98

姓名

葉哲勝(Che-Shen Yeh) 查詢紙本館藏

畢業系所

資訊工程學系

論文名稱

正交多載波分頻多工系統通道估測技術之研究通道估測技術之研究
(A study of channel estimation for OFDM systems )

相關論文

★ 資料儲存系統之渦輪碼與訊號處理研究	★ 10Gb/s MM XFP光收發模組設計與實現
★ 資訊產品自動化測試之研究	★ 高電流密度鰭式氮化鎵高電子遷移率電晶體研究
★ 電子郵件及壓縮檔案解碼之研究	★ 物件輪廓導向之低位元率視訊編碼研究及其應用
★ 插值時序恢復之研究與應用	★ 資料儲存系統之通道研究
★ 全數位化π/4-shifted DQPSK 之分析與實現	★ 校園多媒體無線通訊系統通道編∕解碼器之研究
★ 資料儲存系統之調變碼研究	★ 利用紅外線傳輸動態影像(H.263)之研究
★ 數位式上昇餘弦函數濾波器最佳化設計	★ 資料儲存PRML通道系統之全數位插值時序恢復研究及設計
★ IrTran-P環境下之JPEG影像錯誤偵測與改善	★ FIR濾波器於二冪次係數空間之研究與分析

檔案

[Endnote RIS 格式]

[Bibtex 格式]

[相關文章]

[文章引用]

[完整記錄]

[館藏目錄]

至系統瀏覽論文 ( 永不開放)

摘要(中)

OFDM 系統由於傳輸性能好，被廣泛應用在各種寬頻通信服務。例如：ADSL、 DAB、DVB-T、Japanese ISDB、 ETSI HiperLAN2、以及 IEEE802.11.。傳統OFDM 系統的通道估測皆採用頻域引導波信號，接收端也在頻域利用此引導波信號作通道估測，作者為了使OFDM 系統在行動接收特性更為出色，本文提出三種時域通道估測方法與傳統通道估測方式在『靜態多路徑干擾』、『慢速衰落多路徑干擾』以及『行動接收造成快速衰落』三種通道環境進行估測的研究比較。本文提出三種通道估測方法如下：
lFrequency domain Pilot Time domain Average (FPTA)
lTime domain Pilot Time Cross-correlation (TPTC)
lTime domain Pilot Time Cross-correlation and Time varying Estimation. (TPTCTE)
從理論分析及電腦模擬驗証，OFDM信號經過multipath fading加上AWGN組合的無線通道在時域作通道估測方法比頻域處理明顯改進傳輸性能。本文也針對行動接收因素作廣泛研究，包含行動接收時引入Doppler frequency shift 與 long term fading 以及short term fading，加上short term fading中各多路徑干擾信號因為入射角不同導致通道模式中各個多路徑干擾信號相位變化的角速度皆被考慮在內。
經電腦模擬證實本文提出三種通道估測方法傳輸性能比傳統方式更佳，其研究成果歸納如下：
1.FPTA方法的優點也是技術簡單，pilot to noise ratio大，適用於fading channel，尤其對於小範圍廣播，例如LMDS (Local Multipoint Distribution Service) 通道響應短者，可採用較小的pilot ratio (例如1/32或是1/64)不但節省pilot之overhead，同時通道模式估測特性相當好。但是本方法缺點是pilot ratio較大(例如1/4)時，時域引導信號大，浪費發射功率。
2.TPTC方法具有FPTA方法的優點，卻沒有FPTA的缺點，可適應各種不同通道模式且適合於fading channel。
3.TPTCTE方法不只考慮OFDM symbol內channel的時變特性，利用在時域上有較佳pilot to noise特性精準估測通道模式的時變量，使得在fast fading情形下仍然有出色的表現。所以，TPTCTE方法在Slow-fading與fast-fading中均有最佳的表現
4.當level cross rate高者，fading dip深且多，表示burst error時常出現，可加強TCM correct功能改善性能；若average duration of fade較長時，表示有較長串的burst error，可利用深度較大的interleaving技術，將length長的burst error均勻平配各個TCM packet中來改善性能。
5.TPTCTE對於通道模式時變性(time varying)較嚴重有顯著的改善效果，再配合interleaving and TCM correct功能，可降低Symbol error rate的error-floor現象，提昇OFDM system的傳輸性能。

摘要(英)

The orthogonal frequency division multiplexing (OFDM) system has been widely adopted in both wire line and wireless communication systems, such as ADSL, DAB, DVB-T, Japanese ISDB, ETSI HiperLAN2, IEEE802.11. In OFDM systems channel fading effects are eliminated by the equalization of received signals, where the equalizer coefficients are determined according to results of channel estimation process. The channel estimation is usually accomplished in the frequency domain by inserting pilot tones in OFDM symbols.
In this dissertation, channel estimations of OFDM systems in the time-domain for both slow fading and fast fading channels are investigated. Three time-domain channel estimation methods are proposed in this dissertation as follows:
1.Frequency domain Pilot Time domain Average (FPTA)
2.Time domain Pilot Time Cross-correlation(TPTC)
3.Time domain Pilot Time Cross-correlation with Time varying Estimation. (TPTCTE)
Theoretical analysis reveals that a higher P/N ratio can be obtained with proposed estimation methods. It is also demonstrated from computer simulations, under assumptions of multipath distortion and AWGN channel, the proposed estimation techniques can outperform the conventional estimation techniques in which the channel response is estimated in the frequency domain.
The simulations in this dissertation employ some practical fading channel models of digital transmission. One of these models used is obtained by experimental results of the field-testing of the Digital Television (DTV) related activities of Taiwan. Other channel models used are recommended by the Advanced Television Test Center (ATTC) in the U. S. A. and by the Digital Audio Broadcasting (DAB) project in Europe, with both static and dynamic multipath distortions.
The simulation results reveal that the proposed time-domain channel estimation techniques can perform better than the conventional frequency domain channel estimation technique. The proposed FPTA and TPTC techniques have advantages of low computational complexity and high P/N ratio. The simulation results also demonstrate that the TPTCTE method can improve the performance especially for time varying channel and can reduce the SER error floor. In TPTCE a novel channel estimation and compensation scheme for fast fading channel is employed for OFDM systems using time domain training sequence. Which results in a better performance for both slow fading and fast fading environments.

關鍵字(中)

★ 正交多載波分頻多工系統
★ 通道估測技術

關鍵字(英)

★ channel estimation
★ OFDM

論文目次

Abstract7
1. Introduction9
2. Description of OFDM Channel Models16
2.1 Static Reception Channel Model16
2.2 Mobile Reception Channel Model22
3. Channel Estimation over Slow Fading Channel31
3.1 Description of the Channel Estimation Methods 31
3.2 Analysis of Pilot to Noise Ratio35
3.3 Performance Comparison and Discussion40
4. Channel Estimation over Fast Fading Channel64
4.1 Description of the Channel Estimation Methods 64
4.2 Performance Comparison and Discussion74
5. Conclusion84
References88
Publication List94

參考文獻

1.R. W. Chang, “Synthesis of band-limited orthogonal signals for multichannel data transmission,” Bell Syst. Tech. Journal, Vol.45, Dec. 1966.
2.L. J. Cimini, Jr., “Analysis and simulation of digital mobile channel using orthogonal frequency-division multiplexing,” IEEE Transactions on Communications., Vol. 33, No. 7, July 1985, pp.665-675.
3.J. A. C. Bingham, “multicarrier modulation for data transmission：An idea whose time has come,” IEEE Commun. Magazine, Vol. 28, No. 5, 1990, pp. 5-14.
4.American National Standards Institute（ANSI）.”Asymmetric digital subscriber line（ADSL）metallic inter-face”, Draft American National Standard for Telecommunications, Dec. 1995.
5.P. Shelswell,’ The COFDM modulation system：the heart of digital audio broadcasting,” Elec. Commun. Eng. Journal. June 1995, pp. 127-136.
6.U. Reimer, “Digital Video Broadcasting,” IEEE Communications Magazine, Vol. 36, No. 6, Jun 1998, pp. 104-110.
7.M. Uehara, M. Takada and Kuroda, ”Transmission scheme for the terrestrial ISDB system,” IEEE Trans. on Consumer Electronics, Vol. 45, No. 1, Feb 1999, pp. 101-106.
8.R.van Nee and G. Awater, “New high-rate wireless LAN standards,” IEEE Communications Magazine, Dec 1999, pp. 82-88.
9.N. Morinaga and A. Hashimoto, ”Technical trend of multimedia mobile and broadband wireless access systems,” IEICE Trans. Commun., Vol. E82-B, No. 12, Dec 1999, pp. 1897-1905.
10.Y. Li, N. Seshadri and S. Ariyavisitakul, ”Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels” IEEE Journal on Select, Areas in Communication., Vol. 17, No. 3,Mar 1999, pp. 461-470.
11. H. Sari, G. Karam, and I. Jeanclaude “ Frequency domain equalization of mobile radio and terrestrial broadcast channels”. Global Telecommunication Conference IEEE published, Vol. 1, pp. 1-5, 1994.
12.V. Mignone and A. Morello “CD3-OFDM: A novel demodulation scheme for fixed and mobile receivers”, IEEE Transactions on Communications. Vol.44, No.9, pp.1144~1151, September 1996.
13.Y. Wu and W. Y. Zou “COFDM: An overview”. IEEE Transactions on Broadcasting Vol.41, No.1, pp. 1-7, March 1995.
14.R. Negi and J. Cioffi “Pilot tone selection for channel estimation in a mobile OFDM system”. IEEE Transactions on Consumer Electronics, Vol.44, No3, pp. 1122-1128, August1998.
15.M.-S. Kang and W.-J. Song “A robust channel equalizer for OFDM TV receivers” IEEE. Transactions on Consumer Electronics, Vol.44, No.3, pp. 1129-1133, August 1998.
16.“Grand Alliance Transmission System Selection Test Plan”. SSWP2-1218, Rev.13, January 1994
17.“Characteristics of DAB Receiver”, European Committee for Electro technical Standards, PREN50248, 1996
18.Y. Lin “Shift and Added” property of m-sequence and its application to channel characterization of digital magnetic recording”, IEE Proceedings- Communications, Vol.142. No.3, pp. 135-140, June 1995.
19.“Digital Video Broadcasting (DVB) Framing structure, Channel Coding and Modulation Digital Terrestrial Television (DVB-T)” ETS 300 744, March 1997
20.Y. Wu, and W. Y. Zou, “Orthogonal Frequency Division Multiplexing: A Multiple-Carrier Modulation Scheme”, IEEE Transactions on Consumer Electronics, No. 3, Vol. 41, August 1995.
21.Chini, Y. Wu, M. El-Tanany, and S. Mahmoud, “An OFDM-based Digital ATV Terrestrial Broadcasting System with a Filtered Decision Feedback Channel Estimator”, IEEE Transactions on Broadcasting, Vol. 44, No. 1, pp. 2-11, March 1998.
22.Ledoux “COFDM-6 Field Testing” IEEE Transactions on Consumer Electronics, Vol. 42, No. 3, August 1996, pp. 270~273.
23.M. Mckimon, M. Drangin and G. Sgrignoli“RIBUNE/WGN DTV Field Test”IEEE Transactions on Broadcasting, Vol. 44, No. 3, September 1998, pp. 261~273
24.G. Sgrignoli, W. Bretl, and R. Citta, “VSB Modulation Used for Terrestrial and Cable Broadcasts”, IEEE Transactions on Consumer Electronics, Vol. 41, No. 3, August 1995.
25.Field Test Results of the Grand Alliance HDTV Transmission Subsystem, submitted by MSTV, Cable Labs, and PBS to SS/WP-2 Field Testing Task Force of ACATS, September 16, 1994.
26.“Results of the Terrestrial Broadcast Transmission of the Grand Alliance HDTV System,” submitted by MSTV, Cable Labs, and PBS to SS/WP-2 Field Testing Task Force of ACATS, October 16, 1995.
27.William Y. Zon, Yiyan Wu and Michele Gwillet“Analyses of ATV Transmission Subsystem Field Test Data”, IEEE Transactions on Broadcasting Vol. 42, No. 1. March 1996, pp.1~9
28.Che-Shen Yeh, Shih-Jack Chang, Chiung-Jang Chen, Yinyi Lin, “Digital Television Development in Taiwan”, IEEE International Symposium on Consumer Electronics, October 1998. pp. TPA1-01~06.
29.C.S.Yeh and Y. Lin “Channel Estimation Using Pilot Tons in OFDM Systems” IEEE Trans. on Broadcasting Dec.1999, Vol. 45, Number 04 PP. 400~409
30.“Digital Video Broadcasting (DVB) Framing structure, Channel Coding and Modulation Digital Terrestrial Television (DVB-T)” ETS 300 744, v1.2.1, June 1999.
31.William C.Y. Lee, Mobile Communications Design Fundamental, John Wiley & Sons, New York, 1993.
32.W. C.Y. Lee, Mobile Communications Engineering, McGraw-Hill, New York, 1982.
33.G. Ungerboeck, “Trellis Coded Modulation with Redundant Signal Sets”, IEEE Communications Mag., vol. 27, pp. 5-21, Feb. 1987.
34.R. Negi and J. Cioffi “Pilot tone selection for channel estimation in a mobile OFDM system”. IEEE Transactions on Consumer Electronics, vol.44, no. 3, pp. 1122-1128, August 1998.
35.M.-S. Kang and W.-J. Song “A robust channel equalizer for OFDM TV receivers” IEEE Transactions on Consumer Electronics, vol.44, no.3, pp. 1129-1133, August 1998.
36.Che-Shen Yeh, Yinyi Lin and Yiyan Wu “OFDM System Channel Estimation Using Time-Domain Training Sequence for Mobile Reception of Digital Terrestrial Broadcasting”本篇論文於89年8月被IEEE Broadsting Technology Society 所接受。
37.Che-Shen Yeh, Yinyi Lin and Yiyan Wu“Channel Estimation in OFDM Systems for Terrestrial Broadcasting”本篇論文於89年9月被IEICE Communication society所接受。
38.Che-Shen Yeh, Chiung-Jang Chen, Chih-Cheng Cho, Yinyi Lin“Digital Television Development in Taiwan” 1998 IEEE International Symposium on Consumer Electronics (isce’98), PP. TAP1-01-06
39.Che-Shen Yeh, Shih-Jack Chang, Chih-Cheng Cho, Yinyi Lin “The DTV field tests and the channel model analysis (C-10)” Proceedings of the Second (1999) Radio Science Symposium National Central University December, 20~21, 1999 Chung Li, Taiwan, R. O. C. PP. 117~130
40.葉哲勝、林銀義、陳瓊璋、張世傑、卓志成 “數位通信系統中單載波與多載波傳輸性能之研究”(1998/10)第四屆電腦與通信技術研討會PP. .405 ~ 410
41.Y. Li, L. J. Cimini, Jr. N. R. Sollenberger, “Robust channel estimation for OFDM systems with rapid dispersive fading channel,” IEEE Trans. on Communications., Vol. 46, No. 7,Jul 1998, pp. 902-915.
42.M. Speth, S. Fechtel, G. Fock and H. Meyr, “Broadband transmission using OFDM：System performance and receiver complexity,” International Zurich Seminar on Broadband Communications, Zurich, Switzerland, Feb. 1998, pp. 99-104.
43.P. Hoeher, ”TCM on frequency selective land mobile fading channel,” Triennial International Workshop on Digital Communications, Sept. 1991.
44.F. Classen, M. Speth and H. Meyr , “Channel estimation units for an OFDM system suitable for mobile communications,” Mobile Kommumikation：ITG-Fachbericht, Munchen, Berlin, Sept. 1995.
45.J-J van de Beek, O. Edfors, M. Sandell, S. K. Wilson and P. O. Brjesson, “On channel estimation in OFDM systems,” Vehicular Technology Conf., 1995, pp. 815-819.

指導教授

林銀議(Yin-Yi Lin)

審核日期

2000-12-27

推文