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 U0002-1406200616402000
中文論文名稱 運用RLS頻域等化器之OFDM系統在雷利衰減通道中之績效
英文論文名稱 Performance of OFDM Systems over Rayieigh Fading Channel Using RLS FEQ
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 94
學期 2
出版年 95
研究生中文姓名 李圖恩
研究生英文姓名 Tu-En Lee
學號 693350059
學位類別 碩士
語文別 英文
口試日期 2006-05-30
論文頁數 49頁
口試委員 指導教授-嚴雨田
委員-周勝次
委員-詹益光
中文關鍵字 RLS  OFDM  FEQ  Jakes model  frequency offset  frequency-selective fading  ICI 
英文關鍵字 RLS  OFDM  FEQ  Jakes model  frequency offset  frequency-selective fading  ICI 
學科別分類 學科別應用科學電機及電子
中文摘要 對基於衰減通道的正交分頻多工系統,我們運用具有遞迴均方演算法的頻域等化器來估測信號。本論文採用的衰減通道模型為加入Walsh-Hadamard編碼的修正型傑克模型,我們並以此模型模擬具頻率選擇特性的雷利衰減通道,且都卜勒漂移、頻率偏移和雜訊對系統的影響都會被考慮在其中。我們運用正方形4-QAM的信號於具有16個子通道的正交分頻多工系統做為實驗模擬的基本架構。實驗及討論結果顯示慢速衰減通道整體而言有相當不錯的表現。
英文摘要 For orthogonal frequency division multiplexing (OFDM) systems over fading channels, we apply recursive least-squares (RLS) algorithm to a frequency domain equalizer (FEQ) for signal detection. For fading channel model, we use modified Jakes model with Walsh-Hadamard precoding to simulate frequency-selective Rayleigh fading in our simulation works. Effects on system performance of Doppler spread, frequency offset, and noise are studied. In simulations, square 4-QAM signaling in a 16 subband OFDM system is employed. Study results show that the scheme works well for slow fading channels.
論文目次 CHINESE ABSTRACT I
ENGLISH ABSTRACT II
ACKNOWLEDGEMENT III
CONTENTS IV
LIST OF FIGURES VI
CHAPTER 1 INTRODUCTION 1
CHAPTER 2 MULTIPATH FADING CHANNELS AND PROPAGATION MODELING 5
2.1 Multipath Propagation ……………...…………………….....…... 5
2.2 Rayleigh Fading model……………………………...……………..6
2.3 Other Fading Models…………………………………...…………8
2.3.1 Rice fading…………………….…………...……8
2.3.2 Nakagami fading………………...……...….…...9
2.4 Shadowing………………………………………………………...10
2.5 Frequency Selective and Nonselective (Flat) Fading…………...11
2.6 Modified Jakes Model……………………………………….…...12
CHAPTER 3 QAM SIGNALING SCHEME 15
3.1 Pulse Amplitude Modulation…………………………………….15
3.2 Phase-Shift Keying……………………………………………….16
3.3 Quadrature Amplitude Modulation……………………….……..17

CHAPTER 4 THE OFDM SYSTEM STRUCTURE 19
4.1 An Ideal System………………………………………………....19
4.2 OFDM System with Frequency Offset and Additive White Gaussian Noise……………………………………………….….22
CHAPTER 5 THE FREQUENCY DOMAIN RECURSIVE LEAST-SQUARE EQUALIZER 26
5.1 Frequency Domain Equalization…………………….………...26
5.2 The RLS FEQ Algorithm………………………………………28
CHAPTER 6 SIMULATION RESULTS AND DISCUSSIONS 32
6.1 Learning Curve Performance…………………...……………32
6.2 Symbol Error Rate Performance……………………………..40
CHAPTER 7 CONCLUSIONS 43
7.1 Important Findings………………………………………….…43
7.2 Further Research Possibilities…………………………….......43
REFERENCES 45
LIST OF FIGURES


Figure 4.1 The OFDM system with frequency offset and AWGN………………………...24
Figure 5.1 Bank of linear combining filters……………………………………………….27
Figure 5.2 The RLS FEQ………………………………………………………………….29
Figure 6.1 RLS learning curves for OFDM system over flat fading and frequency-selective fading channels………………………………………………………………...35
Figure 6.2 Effect of carrirer frequency offset on the RLS FEQ performance……………..36
Figure 6.3 Learning curves for a flat fading channel with various Doppler parameters..…37
Figure 6.4 Learning curves for a 2-tap frequency-selective channel with various
Doppler parameters…..………………………………………………………..38
Figure 6.5 Learning curves for the 2-tap frequency-selective channel as in Figure 6.4
with same Doppler parameters but high SNR…………………………………39
Figure 6.6 SER performance of the flat fading channel…………………………………...41
Figure 6.7 SER performance of the frequency-selective channel…………………………42
參考文獻 [1] J.A.C. Bingham, “Multicarrier modulation for data transmission: an idea whose time has come”, IEEE Comm. Magazine, vol. 28, No. 5, May 1990, pp. 5-14.
[2] IEEE Std. 802.11g-2003 (Amendment to IEEE Std 802.11, 1999 Edn. (Reaff 2003) as amended by IEEE Stds 802.11a-1999, 802.11b-1999, 802.11b-1999/Cor 1-2001, and 802.11d-2001).
[3] P. Shelswell, “The COFDM modulation system: The heart of digital audio broadcasting,” Elec. Comm. Eng. Journal, June 1995, pp. 127-136.
[4] U. Reimers, “Digital video broadcasting,” IEEE Comm. Magazine, vol. 36, no. 6, June 1998, pp. 104-110.
[5] H. Sari, G. Karam, and I. Jeanclaude, “Transmission techniques for digital terrestrial TV broadcasting,” IEEE Comm. Magazine, vol. 33, no. 2, Feb. 1995, pp. 100-109.
[6] M. Speth, S.A. Fechtel, G.. Fock, and H. Meyr, “Optimum receiver design for wireless broad-band systems using OFDM. I,” IEEE Trans. Comm., vol. 47, No. 11, Nov. 1999, pp. 1668-1677.
[7] J. G.. Proakis, Digital Communications, New York, McGraw-Hill, 2001.
[8] S. Haykin, Communication Systems, New York, Wiley, 2001.
[9] R. van Nee and R. Prasad, OFDM Wireless Multimedia Communications, Boston, Artech House, 2000.
[10] R. W. Chang, “High-speed multichannel data transmission with bandlimited orthogonal signals,” Bell Sys. Tech. J., vol. 45, Dec. 1966, pp. 1775-1796.
[11] B. R. Saltzberg, “Performance of an efficient parallel data transmission system,” IEEE Trans. Comm. Tech., vol. COM-15, no. 6, Dec. 1967, pp. 805-811.
[12] S. B. Weinstein and P. M. Ebert, “Data transmission by frequency-division multiplexing using the discrete Fourier transform,” IEEE Trans. Comm. Tech., vol. COM-19, no. 5, Oct. 1971, pp. 628-634.
[13] B. Hirosaki, “An analysis of automatic equalizers for orthogonally multiplexed QAM systems,” IEEE Trans. Comm., vol. COM-28, no. 1, Jan. 1980, pp. 73-83.
[14] B. Hirosaki, “An orthogonally multiplexed QAM system using the discrete Fourier transform,” IEEE Trans. Comm., vol. COM-29, no. 7, Jul. 1981, pp. 982-989.
[15] I. Kalet, “The multitone channel,” IEEE Trans. Comm., vol. 37, no. 2, Feb. 1989, pp. 119-125.
[16] W. C. Y. Lee, “Estimate of channel capacity in Rayleigh fading environment,” IEEE Trans. Veh. Tech., vol. 39, no. 3, Aug. 1990, pp. 187-189.
[17] Z. Ma and Y.-I. Kim, “The frequency offset algorithm of the multi-user access for OFDM systems,” IEEE 60th Veh. Tech. Conf., vol. 5, 26-29 Sept. 2004, pp. 3364-3367.
[18] K. W. Kang, J. Ann, and H. S. Lee, “Decision-directed maximum-likelihood estimation of OFDM frame synchronisation offset,” IEEE Elect. Letters, vol. 30, No. 25, 8 Dec. 1994, pp. 2153-2154.
[19] P. H. Moose, “A technique for orthogonal frequency division multiplexing frequency offset correction,” IEEE Comm. Trans., vol. 42, No. 10, Oct. 1994, pp. 2908-2914.
[20] J.J. van de Beek, M. Sandell, and P.O. Borjesson, “ML estimation of time and frequency offset in OFDM systems,” IEEE Sig. Proc., vol. 45, No. 7, July 1997, pp. 1800-1805.
[21] M. Speth, F. Classen, and H. Meyr, “Frame synchronization of OFDM systems in frequency selective fading channels,” 1997 IEEE 47th Veh. Tech., vol. 3, 4-7 May 1997, pp. 1807-1811.
[22] T.M. Schmidl, and D.C. Cox, “Robust frequency and timing synchronization for OFDM,” IEEE Comm. Trans., vol. 45, No. 12, Dec. 1997, pp. 1613-1621.
[23] Y.S. Choi, P.J. Voltz, and F.A.Cassara, “ML estimation of carrier frequency offset for multicarrier signals in Rayleigh fading channels,” IEEE Veh. Tech. Trans., vol. 50, No. 2, March 2001, pp. 644-655.
[24] T. Keller, L. Piazzo, P. Mandarini, and L. Hanzo, “Orthogonal frequency division multiplex synchronization techniques for frequency-selective fading channels,” IEEE Comm. Sel. Areas Jour., vol. 19, No. 6, June 2001, pp. 999-1008.
[25] D. Landstrom, S.K. Wilson, J.-J. van de Beek, P. Odling, and P.O. Borjesson, “Symbol time offset estimation in coherent OFDM systems,” IEEE Comm. Trans., vol. 50, No. 4, April 2002, pp. 545-549.
[26] Z. Ma, C. Zhao, and X. You, “A novel OFDM time and frequency synchronization algorithm,” Inter. Conf. Comm. Tech. Proc. 2003 (ICCT 2003), vol. 2, 9-11 April 2003, pp. 1114-1118.
[27] A.-B. Salberg and A. Swami, “Doppler and frequency-offset synchronization in wideband OFDM,” IEEE Wire. Comm. Trans., vol. 4, No. 6, Nov. 2005, pp. 2870-2881.
[28] M. Hlaing, V.K. Bhargava, and K.B. Letaief, “A combined timing and frequency synchronization and channel estimation for OFDM,” IEEE Comm. Trans., vol. 54, No. 3, March 2006, pp. 416-422.
[29] J.-J. van de Beek, O. Edfors, M. Sandell, S.K. Wilson, and P.O. Borjesson, “On channel estimation in OFDM systems,” 1995 IEEE 45th Veh. Tech., vol. 2, 25-28 July 1995, pp. 815-819.
[30] F. Tufvesson, and T. Maseng, “Pilot assisted channel estimation for OFDM in mobile cellular systems,” 1997 IEEE 47th Veh. Tech., vol. 3, 4-7 May 1997, pp. 1639-1643.
[31] O. Edfors, M. Sandell, J.-J. van de Beek, S.K. Wilson, and P.O. Borjesson, “OFDM channel estimation by singular value decomposition,” IEEE Comm. Trans., vol. 46, No. 7, July 1998, pp. 931-939.
[32] M.-H. Hsieh and C.-H. Wei, “Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency selective fading channels,” IEEE Cons. Elec. Trans., vol. 44, No. 1, Feb. 1998, pp. 217-225.
[33] P. Hoeher and F. Tufvesson, “Channel estimation with superimposed pilot sequence,” Glob. Tel. Conf. (GLOBECOM '99), vol. 4, 1999, pp. 2162-2166.
[34] Y. Li, “Pilot-symbol-aided channel estimation for OFDM in wireless systems,” IEEE Veh. Tech. Trans., vol. 49, No. 4, July 2000, pp. 1207-1215.
[35] S. Coleri, M. Ergen, A. Puri, and A. Bahai, “Channel estimation techniques based on pilot arrangement in OFDM systems,” IEEE Broad. Trans., vol. 48, No. 3, Sept. 2002, pp. 223-229.
[36] M.-O. Pun, M. Morelli, and C.-C.J. Kuo, “Maximum-Likelihood Synchronization and Channel Estimation for OFDMA Uplink Transmissions,” IEEE Comm. Trans., vol. 54, No. 4, April 2006, pp. 726-736.
[37] J. Ahn and H.S. Lee, “Frequency domain equalization of OFDM signals over frequency nonselective Rayleigh fading channels,” Electronics Letters, vol. 29, No. 16, 5 Aug. 1993, pp. 1476-1477.
[38] S. Haykin, Adaptive Filter Theory, New Jersey, Prentice-Hall, 2002.
[39] P. Dent, G.E. Bottomley, and T. Croft, “Jakes fading model revisited,” Electronics Letters, vol. 29, No. 13, 24 June 1993, pp. 1162-1163.
[40] G.L. Stuber, Principles of Mobile Communication 2nd, Boston, Kluwer Academic Publishers, 2001.
[41] L.B. Jackson, Digital Filters and Signal Processing 3rd with MATLAB Exercise, Dordrecht, Kluwer Academic Publishers, 1996.
[42] L. Cimini Jr., “Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing,” IEEE Comm. Trans., vol. 33, No. 7, Jul 1985, pp. 665-675.
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2006-06-23公開。
  • 同意授權瀏覽/列印電子全文服務,於2006-06-23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