簡易檢索 / 詳目顯示

回結果列表
研究生： 許輝利
Felixzihwelly - Hendra Wijaya
論文名稱： 低密度奇偶檢查碼在馬可夫高斯通道下之效能分析
Low-Density Parity Check Decoding Over Markov Gaussian Channel
指導教授： 曾德峰
Der-Feng Tseng
口試委員: 韓永祥
Yunghsiang S. Han
張立中
Li-Chung Chang
學位類別： 碩士
Master
系所名稱： 電資學院 - 電機工程系
Department of Electrical Engineering
論文出版年： 2015
畢業學年度： 103
語文別： 英文
論文頁數： 60
中文關鍵詞： 低密度奇偶檢查碼 、記憶性通道 、最大事後機率估測
外文關鍵詞： Low-Density Parity Check Codes, Memory Channel, MAP Estimation
相關次數： 點閱：490  下載：0 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  •  上一筆

    • 在無線通訊系統下，記憶型脈衝雜訊一直是無法避免的，在本文使用LDPC解碼並結合最大事後機率的估測(MAP Estimator)去對抗記憶性脈衝雜訊。在不用知道太多資訊下，此種估測方法能有效的偵測出通道狀態，而詳細步驟和複雜度分析將會在本文中作介紹。
    在模擬結果中顯示，proposed decoder能對抗叢錯誤較長的脈衝雜訊，且proposed decoder的效能與標竿效能非常接近，而所謂的標竿就是運用所有通道資訊。另外再雷利衰減通道中，proposed decoder一樣有著不錯的解碼效能。

    Memory impulse noise becomes one of the problems in the wired and wireless communication systems. To address the challenge of the memory impulse noise, a Low-Density Parity Check (LDPC) decoding combined with the Maximum A Priori (MAP) Estimation was devised. By estimating the channel states, while ignoring the impulse statistics, the LDPC decoder could perform well. More detailed steps and complexity analysis of the proposed decoder were offered.
    There are three algorithms tested for the proposed decoder to investigate the robustness of the algorithm. The simulation results indicated that the involvement of the MAP Estimator in the decoder’s iteration is not necessary. The simulation results also indicated that the proposed decoder performed well against the two-state memory channel with longer bad states; and yet it has a loss about 0.3 dB compared to the optimum decoder in the memory channel with short bad states. The bit error probability error attained using the proposed decoder is close to that of an optimal decoder, which employs the impulse statistics. A maximum number of iteration equal to 50 is sufficient to produce the performance comparable to the optimum decoder in the memory channel without Rayleigh fading. The performance of the proposed decoder over a Rayleigh Fading with two-state Markov Gaussian channel is also investigated, in which the proposed decoder still needs improvement. The performance of the two-state proposed decoder over three-state Markov Gaussian channel is also investigated, where the decoder could works well. The proposed decoder still shows weakness toward the Rayleigh Fading with three-state Markov Gaussian channel.

    MASTER THESIS RECOMMENDATION FORM ................................................................. ii QUALIFICATION FORM BY MASTER’S DEGREE EXAMINATION COMMITTEE .... iii ABSTRACT .............................................................................................................................. iv 摘要............................................................................................................................................ v ACKNOWLEDGEMENTS ...................................................................................................... vi TABLE OF CONTENTS ......................................................................................................... vii LIST OF FIGURES .................................................................................................................. ix LIST OF TABLES .................................................................................................................... xi Chapter 1 INTRODUCTION ..................................................................................................... 1 1.1 Background .............................................................................................................. 1 1.2 Objectives ................................................................................................................ 3 1.3 Organization of the Thesis ....................................................................................... 3 Chapter 2 LITERATURE REVIEW .......................................................................................... 4 2.1 Overview on LDPC Codes....................................................................................... 4 2.1.1 Encoding ......................................................................................................... 6 2.1.2 Decoding ......................................................................................................... 6 2.2 Maximum a Posteriori (MAP) Algorithm................................................................ 9 Chapter 3 SYSTEM MODEL .................................................................................................. 10 3.1 Model ..................................................................................................................... 10 3.1.1 System Model over Markov Gaussian Channel ............................................ 10 3.1.2 System Model over Rayleigh Fading with Markov Gaussian Channel ........ 11 3.2 Encoder .................................................................................................................. 11 3.3 Noise Model ........................................................................................................... 12 3.3.1 Two-state Markov Gaussian Channel ........................................................... 12 3.3.2 Three-state Markov Gaussian Channel ......................................................... 13 3.4 Rayleigh Fading with Markov Gaussian Channel ................................................. 14 3.5 LDPC Decoding Algorithm over Markov Gaussian Channel ............................... 15 3.5.1 Optimum Decoder (Benchmark)................................................................... 15 3.5.2 Mixture Gaussian Decoder ........................................................................... 16 3.5.3 Refined and Proposed Decoder ..................................................................... 18 3.6 Algorithms for LDPC Decoding over Rayleigh Fading with Markov Gaussian Channel .................................................................................................................. 28 3.7 Decoder Computational Complexity ..................................................................... 29 Chapter 4 RESULT AND DISCUSSION................................................................................ 31 4.1 Performance over Two-State Markov Gaussian Channel ...................................... 31 4.1.1 Performance Comparison between Algorithms ............................................ 31 4.1.2 Effect of number of Iterations ....................................................................... 37 4.2 Performance over Rayleigh Fading with Two-State Markov Gaussian Channel .. 40 4.3 Performance over Three-State Markov Gaussian Channel using Two-State Proposed Decoder .................................................................................................. 42 4.4 Performance over Rayleigh Fading with Three-State Markov Gaussian Channel using Two-State Proposed Decoder ....................................................................... 44 Chapter 5 CONCLUSION ....................................................................................................... 46 5.1 Conclusion ............................................................................................................. 46 5.2 Future Works ......................................................................................................... 46 REFERENCES ........................................................................................................................ 48

    [1] F. G. Mengistu, T. Der-Feng, Y. S. Han, M. A. Mulatu, and C. Li-Chung, "A Robust Decoding Scheme for Convolutionally Coded Transmission Through a Markov Gaussian Channel," IEEE Trans. Veh. Technol., vol. 63, pp. 4344-4356, Nov. 2014.
    [2] T. Der-Feng, F. G. Mengistu, Y. S. Han, M. Abera Mulatu, C. Li-Chung, and T. Tzung-Ru, "Robust Turbo Decoding in a Markov Gaussian Channel," IEEE Wireless Communications Letters, vol. 3, pp. 633-636, Dec. 2014.
    [3] J. Garcia-Frias, "Decoding of low-density parity-check codes over finite-state binary Markov channels," IEEE Trans. Commun., vol. 52, pp. 1840-1843, 2004.
    [4] D. Fertonani and G. Colavolpe, "On reliable communications over channels impaired by bursty impulse noise," IEEE Trans. Commun., vol. 57, pp. 2024-2030, July 2009.
    [5] J. C. Moreira and P. G. Farrell, Essentials of Error-Control Coding. Chichester: Wiley, 2006.
    [6] R. G. Gallager, "Low-density parity-check codes," IRE Trans. Inf. Theory, vol. 8, pp. 21-28, Jan. 1962.
    [7] W. Ryan and S. Lin, Channel Codes: Classical and Modern. Cambridge: Cambridge University Press, 2009.
    [8] A. Patil, S. Sonavane, and D. Rathod, "Review on: Iterative Decoding schemes of LDPC codes," International Journal of Engineering Research and Applications (IJERA), vol. 3, pp. 1837-1840, Mar. 2013.
    [9] H. Nakagawa, D. Umehara, S. Denno, and Y. Morihiro, "A decoding for low density parity check codes over impulsive noise channels," in 2005 International Symposium on Power Line Communications and Its Applications, 2005, pp. 85-89.
    [10] R. Pighi, M. Franceschini, G. Ferrari, and R. Raheli, "Fundamental performance limits of communications systems impaired by impulse noise," IEEE Trans. Commun., vol. 57, pp. 171-182, Jan. 2009.
    [11] D. Fertonani and G. Colavolpe, "A robust metric for soft-output detection in the presence of class-A noise," IEEE Trans. Commun., vol. 57, pp. 36-40, Jan. 2009.
    [12] M. Mushkin and I. Bar-David, "Capacity and coding for the gilbert-elliott channels," IEEE Trans. Inf. Theory, vol. 35, pp. 1277-1290, Nov. 1989.
    [13] L. Hanqing and J. Garcia-Frias, "Low-density generator matrix codes for indoor and markov channels," IEEE Trans. Wireless Commun., vol. 6, pp. 1436-1445, Apr. 2007.
    [14] R. J. McEliece, "On the BCJR trellis for linear block codes," IEEE Trans. Inf. Theory, vol. 42, pp. 1072-1092, Jul. 1996.
    [15] W. Wei, H. Sangjin, and Y. Do-Sik, "Block length of LDPC codes in fading channels," in The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring., 2003, pp. 1876-1880 vol.3.
    [16] S. Lin and D. J. Costello, Error Control Coding: Fundamentals and Applications. Upper Saddle River: Pearson-Prentice Hall, 2004.
    [17] D. Fertonani, A. Barbieri, and G. Colavolpe, "Reduced-Complexity BCJR Algorithm for Turbo Equalization," IEEE Trans. Commun., vol. 55, pp. 2224-2224, Dec. 2007.
    [18] A. J. Goldsmith and P. P. Varaiya, "Capacity, mutual information, and coding for finite-state Markov channels," IEEE Trans. Inf. Theory, vol. 42, pp. 868-886, May 1996.
    [19] M. P. C. Fossorier, M. Mihaljevic, and H. Imai, "Reduced complexity iterative decoding of low-density parity check codes based on belief propagation," IEEE Trans. Commun., vol. 47, pp. 673-680, May 1999.
    [20] T. K. Moon, Error Correction Coding: Mathematical Methods and Algorithms. New Jersey: Wiley, 2005.

    無法下載圖示 全文公開日期 2020/06/29 (校內網路)
    全文公開日期 本全文未授權公開 (校外網路)
    全文公開日期 2025/06/30 (國家圖書館：臺灣博碩士論文系統)
    QR CODE