(3.238.173.209) 您好!臺灣時間:2021/05/09 16:55
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:陳鼎堯
研究生(外文):Ting-yao Chen
論文名稱:展頻通訊系統接收機之演算法與表現評估
論文名稱(外文):Algorithm and Performance Evaluation of Spread Spectrum Communication Receivers
指導教授:馮世邁
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:電信工程學研究所
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2004
畢業學年度:92
語文別:英文
論文頁數:82
中文關鍵詞:展頻演算法通訊系統
外文關鍵詞:Spread SpectrumCommunication SystemCDMACCK
相關次數:
  • 被引用被引用:0
  • 點閱點閱:117
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
對於操作於頻率選擇性頻道中之上鏈非同步直序多碼分工(DS-CDMA)系統,可利用其特殊性質採用較有效率之接收機架構來降低系統複雜度。而前白化削樹(PWTP)演算法也可套用。我們提出了一種PWTP之降態修改,稱之為代表點(RP)演算法,其可進一步降低大信號星群(signal constellation)系統之複雜度。模擬結果顯示,在相同複雜度下,代表點演算法之表現優於傳統演算法。
互補分碼鍵控(CCK)是一種非線性編碼調變。在多路徑環境中,傳統等化器可能輸出無效的CCK序列。我們提出了加入限制路徑的序列估測演算法,其利用了碎碼間的特殊關係,並保證輸出有效的序列。最後,我們使用電腦模擬以比較並評估各演算法之表現。
For uplink asynchronous direct sequence code division multiple access (DS-CDMA) systems in frequency-selective channels, efficient receiver structures utilizing the special properties of the systems can be applied to lower complexity. The pre-whitening tree pruning (PWTP) algorithm can be used with the structures. We propose the representative point (RP) algorithm, which is a reduced-state modification to PWTP algorithm, to further lower the complexity when large constellations are used. Simulation shows that RP outperforms the traditional algorithm with complexity being equal.
Complementary code keying (CCK) is a nonlinear coded modulation. In multipath environment, traditional equalizers regard each chip as an independent symbol and may output invalid CCK sequences. We propose sequence estimation with restricted path (SERP) algorithm, which utilizes certain relationships between chips of CCK sequences and guarantees outputting valid sequences. Simulation is used to compare and evaluate the algorithms.
摘要 i
誌謝 iii
Abstract v
Contents vii
List of Figures ix
List of Tables xi
Chapter 1 Introduction 1
Chapter 2 Signal Models of Spread Spectrum Communications Systems 5
2.1 General Signal Model for Linearly Modulated System 6
2.2 Signal Model for DS-CDMA Systems 9
2.2.1 Downlink Synchronous DS-CDMA in Flat Channels 9
2.2.2 Uplink Asynchronous DS-CDMA in Multipath Channels 12
2.2.3 A Note on the Spreading Sequences for DS-CDMA 15
2.3 Other non-CDMA Spread Spectrum Systems 17
2.3.1 Signal Model for Direct Sequence Spread Spectrum Systems 17
2.3.2 Signal Model for Complementary Code Keying Systems 19
Chapter 3 Conventional Multiuser Detection 23
3.1 Detection in CDMA Systems 24
3.2 Conventional Single-User Matched Filter Receiver 24
3.3 Optimal Multiuser Detection 26
3.4 Suboptimal MUDs 27
3.4.1 Linear Detectors 28
3.4.2 Nonlinear Detectors 30
3.4.3 Near-Optimal Pre-Whitening Tree Pruning (PWTP) Detector 34
Chapter 4 Low Complexity Structures and Proposed Algorithm 39
4.1 System Parameters 40
4.2 Efficient Receiver Structure 41
4.2.1 Iterative Block-wise Detector (IBD) 42
4.2.2 Efficient Cholesky Factorization 43
4.3 Proposed Algorithm for PWTP 44
4.3.1 Representative Point Algorithm Description 45
4.3.2 Complexity Comparison 49
Chapter 5 Receiver Algorithms for WLAN Systems 51
5.1 Detection for CCK Systems 52
5.2 Iterative Interference Cancellation (IIC) 54
5.3 Chip Level Detector 56
5.3.1 Chip Level Decision Feedback Equalizer for CCK 57
5.3.2 Sequence Estimation with Restricted Path for CCK 60
Chapter 6 Simulation Results 65
6.1 Simulation Results for DS/CDMA 65
6.1.1 Simulation Parameters 65
6.1.2 Simulation Results for DS/CDMA 66
6.2 Simulation Results for CCK 73
6.2.1 Simulation Parameters 73
6.2.2 Simulation Results 73
Chapter 7 Conclusion 77
Bibliography 79
[1]S. Haykin, Communications Systems, 4th ed: Wiley Text Books, 2000.
[2]P. G. Flikkema, "Spread-spectrum techniques for wireless communica-tion," Signal Processing Magazine, IEEE, vol. 14, pp. 26-36, 1997.
[3]M. B. Pursley, "Direct-sequence spread-spectrum communications for multipath channels," Microwave Theory and Techniques, IEEE Trans-actions on, vol. 50, pp. 653-661, 2002.
[4]T. S. Rappaport, Wireless Communications: Principles and Practice, 2nd ed: Prentice Hall, 2001.
[5]J. G. Proakis, Digital Communications, 4th ed: McGraw Hill, 2001.
[6]A. J. Viterbi, CDMA: Principles of Spread Spectrum Communications: Addison-Wesley, 1995.
[7]S. Verdu, Multiuser Detection: Cambridge University Press, 1998.
[8]A. Duel-Hallen, J. Holtzman, and Z. Zvonar, "Multiuser detection for CDMA systems," Personal Communications, IEEE [see also IEEE Wireless Communications], vol. 2, pp. 46-58, 1995.
[9]S. Moshavi, "Multi-user detection for DS-CDMA communications," Communications Magazine, IEEE, vol. 34, pp. 124-136, 1996.
[10]L. Wei, L. K. Rasmussen, and R. Wyrwas, "Near optimum tree-search detection schemes for bit-synchronous multiuser CDMA systems over Gaussian and two-path Rayleigh-fading channels," Communications, IEEE Transactions on, vol. 45, pp. 691-700, 1997.
[11]Y.-L. Li, "Tree-Pruning and Sorting Algorithms and Signal Dimen-sionality Issues for Multi-User Detection in DS-CDMA and MC-CDMA," National Taiwan University, June 2002.
[12]"IEEE Std 802.11-1997 Information Technology- telecommunications And Information exchange Between Systems-Local And Metropolitan Area Networks-specific Requirements-part 11: Wireless Lan Medium Access Control (MAC) And Physical Layer (PHY) Specifications," in IEEE Std 802.11-1997, 1997, pp. i-445.
[13]"Supplement to IEEE standard for information technology telecom-munications and information exchange between systems - local and metropolitan area networks - specific requirements. Part 11: wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: high-speed physical layer in the 5 GHz band," in IEEE Std 802.11a-1999, 1999.
[14]K. Halford, S. Halford, M. Webster, and C. Andren, "Complementary code keying for RAKE-based indoor wireless communication," pre-sented at Circuits and Systems, 1999. ISCAS ''99. Proceedings of the 1999 IEEE International Symposium on, 1999.
[15]C. Andren, "Achieving Ethernet Rates in Wireless LANs," presented at IIC, Taipei, 1999.
[16]S. Hara and R. Prasad, "Overview of multicarrier CDMA," Communi-cations Magazine, IEEE, vol. 35, pp. 126-133, 1997.
[17]Y.-L. Li and Y. Lee, "A novel low-complexity near-ML multiuser de-tector for DS-CDMA and MC-CDMA systems," presented at Global Telecommunications Conference, 2002. GLOBECOM ''02. IEEE, 2002.
[18]T. G. initiative, "3rd generation partnership project; technical specifica-tion group radio access network; spreading and modulation (FDD) (re-lease 4)," 3G TS 25.213 V4.1.0, Jun. 2001.
[19]C. Heegard, J. T. Coffey, S. Gummadi, P. A. Murphy, R. Provencio, E. J. Rossin, S. Schrum, and M. B. Shoemake, "High performance wire-less Ethernet," Communications Magazine, IEEE, vol. 39, pp. 64-73, 2001.
[20]Haykin, Adaptive Filter Theory, 4th ed: Prentice Hall, 2001.
[21]C.-C. Hsu, "Multi-Stage Weighted Interference Cancellation and Deci-sion Feedback Equalization with User Sorting and Receiver Diversity for MIMO CDMA Systems," June 2003.
[22]G. H. Golub and C. F. V. Loan, Matrix Computations, 3rd ed: Johns Hopkins Univ Pr, Nov. 1996.
[23]P. D. Alexander and L. K. Rasmussen, "On the windowed Cholesky factorization of the time-varying asynchronous CDMA channel," Communications, IEEE Transactions on, vol. 46, pp. 735-737, 1998.
[24]Y. Lee, "Maximum Likelihood Sequence Estimation," in Lecture Note. E.E. Department, National Taiwan University, 2001.
[25]Y. Lee, "FIR Decision Feedback Equalizer," in Lecture Note. E.E. De-partment, National Taiwan University, 2001.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
系統版面圖檔 系統版面圖檔