淡江大學覺生紀念圖書館 (TKU Library)
進階搜尋


下載電子全文限經由淡江IP使用) 
系統識別號 U0002-1412201016311000
中文論文名稱 非完美通道估計對正交分頻多工系統運用單一時隙之最大概似估算法頻率追蹤之影響
英文論文名稱 Impact of Imperfect Channel Estimation on Maximum-Likelihood-Based OFDM Frequency Tracking Using Single Time-Slot Pilot
校院名稱 淡江大學
系所名稱(中) 電機工程學系碩士班
系所名稱(英) Department of Electrical Engineering
學年度 99
學期 1
出版年 100
研究生中文姓名 吳振明
研究生英文姓名 Chen-Ming Wu
學號 698440020
學位類別 碩士
語文別 英文
口試日期 2010-12-10
論文頁數 45頁
口試委員 指導教授-嚴雨田
委員-易志孝
委員-曾憲威
中文關鍵字 正交分頻多工系統  最大概似估算法  線性最小均方誤差  通道估計 
英文關鍵字 Orthogonal frequency division multiplexing (OFDM)  maximum likelihood estimation  linear minimum mean square error (LMMSE)  Cramer-Rao bound (CRB)  channel estimation 
學科別分類 學科別應用科學電機及電子
中文摘要 此篇論文所討論的是在如何在正交分頻多工系統裡處理精確的頻率追蹤。對精確的頻率追蹤而言,一般常使用一個或多個完整的正交多頻分工的導航區塊或是訓練資料,在時域或頻域之中來執行頻率偏移的估測。這裡我們所探討的方法是使用在時域中所接收到正交分頻多工的區塊資料中挑選一個單一時隙樣本,而不是採用多重樣本。這樣可以大大的簡化計算複雜度,而且仍然可以達到合理的頻率追蹤效能。我們的單一樣本的最大頻率偏移估計器可被證實是不偏的,當訊號雜訊比增加時,它的均方誤差將趨近於CRB。
英文摘要 This thesis deals with fine frequency tracking in orthogonal frequency division multiplexing (OFDM) systems. The usual practice for fine frequency tracking is to use multiple or an entire OFDM block of pilot or training data, either in the time domain or in the frequency domain to perform frequency offset estimation. Here we show that, instead of the elaborate approach of using multiple pilot samples, the problem can be greatly simplified by using only a single pilot sample from a selected time slot in the received time-domain OFDM block to still achieve reasonable tracking performance. It is proven that our single sample ML frequency offset estimator tends to be unbiased and its mean square error (MSE) will approach the Cramer-Rao bound (CRB) as SNR is increased.
論文目次 ACKNOWLEDGEMENT I
CHINESE ABSTRACT II
ENGLISH ABSTRACT III
CONTENTS IV
LIST OF FIGURES V
CHAPTER 1 INTRODUCTION 1
CHAPTER 2 OFDM PRINCIPLE AND STRUCTURE 4
2.1 Introduction………………………………………………………4
2.2 Mathematical Description of an OFDM Signal and System…..9
2.3 Frequency Offset………………………………………………..12
CHAPTER 3 MAXIMUM LIKEHOOD ESTIMATION 17
CHAPTER 4 ML TRACKING TECHNIQUE BASED ON
A SINGLE TIME SLOT SAMPLE 21
4.1 Signal model 21
4.2 ML Frequency Tracking Based on
Signal Time Slot Sample …………………….22
CHAPTER 5 A DISCUSSION ON THE BIAS NATURE OF
ML FREQUENCY OFFSET ESTIMATOR 26
CHAPTER 6 EFFECT OF IMPERFECT CHANNEL ESTIMATION 31
CHAPTER 7 SIMULATION RESULTS 33
CHAPTER 8 CONCLUSION 41
REFERENCE 42
LIST OF FIGURE


Figure 2.1.1 Data transmission using multicarriers …5
Figure 2.1.2 Guard Interval protect …6
Figure 2.1.3 Concept of cyclic prefix …7
Figure 2.1.4 …8
Figure 2.2.1 Baseband OFDM Transmitter 10
Figure 2.2.2 Baseband OFDM Receiver (cyclic prefix removal omitted)………..13
Figure 2.2.3 The OFDM system structure………………………………………....16
Figure 7.1 presents plots of the frequency offset estimator variance or MSE vs. SNR , including CRB………………………………………………….36
Figure 7.2 (a) arctangent vs. arcsine of …………………………………..37
Figure 7.2 (b) arctangent vs. arcsine of …………………………………..38
Figure 7.3 (a) Percentage errors of all subcarrier channel estimates uniformly distributed over …....………………………………….39
Figure 7.3 (b) Percentage errors of all subcarrier channel estimates uniformly distributed over ……………………………………….40
參考文獻 [1] M. Luise and R. Reggiannini, “Carrier frequency acquisition and tracking for OFDM systems,” IEEE Trans. Commun., vol. 19, no. 11, pp. 1590-1598, Nov. 1996.
[2] T. Keller, L. Piazzo, P. Mandarini, and L. Hanzo, “Orthogonal frequency division multiplex synchronization techniques for frequency-selective fading channels,” IEEE J. Selective Areas in Commun., vol. 19, no. 6, pp. 999-1008, June 2001.
[3] F. Classen and H. Meyr, “Frequency synchronization algorithms for OFDM systems suitable for communication over frequency selective fading channels,” IEEE VTC, vol. 3, June 1994, pp. 1655-1659.
[4] T. M. Schmidl and D. C. Cox, “Robust frequency and timing synchronization,” IEEE Trans. Commun., vol. 45, no. 12, pp.1613-1621, Dec. 1997.
[5] M. Morelli and U. Mengali, “An improved frequency offset estimator for OFDM applications,” IEEE Commun. Lett., vo. 3, no. 3, pp.75-77, Mar. 1999.
[6] F. Z. Merli and G. M. Vitetta, “Iterative ML-based estimation of carrier frequency offset, channel impulse response and data in OFDM transmissions,” IEEE Trans. Commun., vol. 56, no. 3, pp.497-506, Mar. 2008.
[7] X. Ma, H. Kobayashi, and S. C. Schwartz, “Joint frequency offset and channel estimation for OFDM,” Proc. IEEE GLOBECOM 2003, vol. 1, Dec. 2003, pp.15-19
[8] Y-S Choi, P. J. Voltz, and F. A. Cassara, “ML estimation of carrier frequency offset for multicarrier signals in Rayleigh fading channels,” IEEE Trans. Veh. Technol., vol. 50, no. 2, pp. 644-655, Mar. 2001.
[9] T. Cui and C. Tellamura, “Maximum-likelihood carrier frequency offset estimation for OFDM systems over frequency-selective fading channels,” 2005 IEEE Int’l Conf. on Commun., vol. 4, May 2005, pp. 2506-2510.
[10] L. Zheng, W. Cheng, J. Hu, and D. Yuan, “The ML frequency tracking algorithm for OFDM systems based on pilot symbols and decision data,” IEEE Symp. Microwave, Antenna, Propagation, and EMC Technol (MAPE 2005), vol. 2, Aug. 2005, pp. 1611-1614.
[11] M. Luise, M. Marselli, and R. Reggiannini, “Low-complexity blind carrier frequency recovery for OFDM signals over frequency-selective radio channels,” IEEE Trans. Commun., vol. 50, no. 7, pp. 1182-1188, July 2002.
[12] S. Attallah, Y. Wu, and J. W. M. Bergmans, “Low complexity blind estimation of residual carrier offset in orthogonal frequency division multiplexing based wireless local network systems,” IET Commun., vol. 1, no. 4, pp. 604-611, 2007.
[13] P. O. Borjesson, O. Edfors, M. Sandell, J. J. Van de Beek, and S. K. Wilson, “On channel estimation in OFDM systems,” Proceeding IEEE 45th Veh. Technol. Conf., Chicago, Il., 1995, pp. 815-819.
[14] P. O. Borjesson, O. Edfors, M. Sandell, J. J. Van de Beek, and S. K. Wilson, “OFDM channel estimation by singular value decomposition,” IEEE Trans. Commun., vol. 46, pp. 931-938, July 1998.
[15] Y. Li, “Pilot-symbol-aided channel estimation for OFDM in wireless systems,” IEEE Trans. Veh. Technol., vol. 49, pp. 1207-1215, July 2000.
[16] M. Morelli and U. Mengali, “A comparison of pilot aided channel estimation methods for OFDM systems,” IEEE Trans. Signal Processing, vol. 49, no. 12, pp. 3065-3073, Dec. 2001.
[17] T. Cui and C. Tellambura, “Robust joint frequency offset and channel estimation for OFDM systems,” Proc. IEEE Veh. Technol. Conf., vol. 1, Sep. 26-29, 2004, pp. 603-607.
[18] J-H. Lee, J. C. Han, and S-C. Kim, “Joint carrier frequency synchronization and channel estimation for OFDM systems via the EM algorithm,” IEEE Trans. Veh. Technol., vol. 55, no. 1, pp. 167-172, Jan. 2006.
[19] L. L. Scharf, Statistical Signal Processing, Reading, MA, Addison-Wesley, 1991.
[20] M. Morelli and U. Mengali, “Carrier-frequency estimation for transmissions over selective channels,” IEEE Trans. Commun., vol. 48, no. 9, pp. 1580-1589, Sep. 2000.
[21] P. L. Meyer, Introductory Probability and Statistical Applications’ Reading, MA, Addison-Wesley, 1970.
[22] A. Peled and A. Ruiz, “Frequency domain data transmission using reduced computationally complexity algorithms,” in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964–967, April 1980.
[23] S. Haykin, Adaptive Filter Theory, 4th ed. Prentice Hall, 2002.
[24] M. Morelli, C.-C. Jay Kuo, Man-On Pun, “Synchronization Techniques for Orthogonal Frequency Division Multiple Access (OFDMA):A Tutorial Review” Proceeding of the IEEE, pp. 1394 – 1427, July 2007
[25] J. G. Proakis, Digital Communications, 4th ed. New York: McGraw-Hill, 2001.
[26] O. Edfors, M. Sandell, J-J van de Beek, S. K. Wilson, and P. O. Borjesson, “OFDM channel estimation by singular value decomposition,” IEEE Trans. Comm., vol. 46, no. 7, July 1998, pp. 931-939.
[27] X. Ma, H. Kabayashi, and S. C. Schwartz,, “Joint frequency offset and channel estimation for OFDM,” IEEE Global Telecomm. Conf. 2003, Dec. 2003, vol.3, pp. 15-19.
[28] L. L. Scharf, Statistical Signal Processing, Reading, MA., Addison-Wesley, 1991.

論文使用權限
  • 同意紙本無償授權給館內讀者為學術之目的重製使用,於2011-02-23公開。
  • 同意授權瀏覽/列印電子全文服務,於2011-02-23起公開。


  • 若您有任何疑問,請與我們聯絡!
    圖書館: 請來電 (02)2621-5656 轉 2281 或 來信