臺灣博碩士論文加值系統

正交分頻多工(orthogonal frequency division multiplexing, OFDM)是一種能夠減緩延遲傳播效能的多工技術，特別是用在非頻率選擇性的頻率衰減通道。因此，研究在不同非頻率選擇性衰落通道OFDM系統執行效能是具有極大的利益。OFDM已成為新的無線通訊應用中最熱門之傳輸調變選擇。基於此，本文仍朝此一方向，利用正交分頻多工信號調變方法，將探討正交分頻多工系統工作於非頻率選擇性衰落通道呈現瑞雷(Rayleigh)分佈、萊斯(Ricean)分佈統計特性時的系統效能分析。並假設接收端利用選擇性分集(selective combining, SC)方法，當非頻率選擇性衰落通道呈現韋布(Weibull)分佈的統計特性，研究正交分頻多工系統在不同的衰落變因係數下之系統效能分析。

The OFDM (orthogonal frequency division multiplexing) signaling is one kind of "Multi-Carrier" technology, which can slow down delayed transmission especially for operating at frequency non-selective fading channels. Therefore, it gains quite large profit making a study of executing efficiency at different frequency non-selective fading channels. The OFDM system has become the most popular choice of transmission modulation in the new wireless communication field. Hence, in this article utilize a method of OFDM modulation to explore the statistical characteristic of distributions of Rayleigh、Ricean、Weibull while working in fading channel. And then use SC(selective combining) at the output of receiver to research efficiency analysis of OFDM system under different fading factor.

封面內頁
簽名頁
授權書...................................iii
中文摘要..................................iv
英文摘要..................................v
誌謝......................................vi
目錄......................................vii
圖目錄....................................x
表目錄....................................xii

第一章　緒論
1.1研究動機與目的..........................1
1.2論文架構................................2
第二章　正交分頻多工系統
2.1正交分頻多工系統簡介......................4
2.2正交特性.................................5
2.3多重路徑衰減..............................6
2.4 保護區間特性.............................8
2.5正交分頻多工調變原理......................10
2.6發射器/接收器模型.........................15
2.6.1 編碼器................................16
2.6.2 對應..................................16
2.6.3 插序..................................16
2.6.4串列轉並列..............................17
2.6.5並列轉串列..............................18
2.6.6數位/類比轉換器.........................19
第三章　無線通訊衰落通道
3.1無線通道特性之描述.........................20
3.1.1無線衰落通道種類之型態....................20
3.1.2多路徑衰減通道之模型......................24
3.2衰落通道的數學模型..........................24
3.3 Normal(Gaussian)衰落分佈..................27
3.3.1單變數常態分佈............................27
3.3.2雙變數常態分佈............................29
3.4 Rayleigh 衰落分佈..........................30
3.5 Ricean 衰落分佈............................32
3.6 Nakagami-m衰落分佈.........................34
3.7 Weibull 模型...............................36
第四章 正交分頻多工系統工作於非頻率選擇性衰落通道的效能
分析無線通訊衰落通道
4.1分集合成技術.................................41
4.2選擇性合成(selective combining, SC)..........42
4.3正交分頻多工系統工作於非頻率選擇性衰落通道
呈現Ricean分佈之系統效能分析......................43
4.4正交分頻多工系統工作於非頻率選擇性衰落通道
呈現Rayleigh分佈之系統效能分析....................45
4.5.正交分頻多工系統工作於非頻率選擇性衰落通道
呈現Weibull分佈之系統效能分析.....................47
第五章 結論......................................54
參考文獻.........................................55

圖目錄

圖2.1基本OFDM系統................................5
圖2.2正交副載波...................................6
圖2.3多重路徑示意圖................................7
圖2.4分頻多工與正交分頻多工的差異....................7
圖2.5保護區間GI示意圖...............................8
圖2.6.a未加入保護區間(GI)...........................8
圖2.6.b加入保護區間(GI).............................9
圖2.7在接收端不同取樣時序位置之符碼產生的影響...........9
圖2.8正交分頻多工系統架構圖..........................14
圖2.9正交分頻多工系統發射機架構圖.....................15
圖2.10正交分頻多工系統接收器架構......................16
圖2.11傳統多重載波調變系統架構圖......................18
圖3.1小尺度衰減訊號..................................21
圖3.2多路徑傳輸衰落效應...............................25
圖3.3時變通道脈衝響應.................................27
圖3.4單變數Gaussian衰落信號包封機率密度函數.............28
圖3.5 Rayleigh 衰減信號包封機率密度函數.................31
圖3.6 Ricean分佈在不同K值時的機率密度函數................34
圖3.7 Nakagami-m分佈在不同 值時的機率密度函數.............35
圖3.8依賴因子 和相關係數 與Weibull衰落參數 之關係..........39
圖4.1選擇性分集合成系統方塊圖.............................42
圖4.2正交分頻多工系統工作於非頻選擇性衰落通道呈現
Ricean分佈之效能........................................45
圖4.3正交分頻多工系統工作於非頻選擇性衰落通道呈現
Rayleigh分佈之效能......................................47
圖4.4正交分頻多工系統工作於非頻選擇性衰落通道呈現
Weibull分佈之效能( 變動, )...............................51
圖4.5正交分頻多工系統工作於非頻選擇性衰落通道呈現
Weibull分佈之效能( 變動, )...............................52
圖4.6正交分頻多工系統工作於非頻選擇性衰落通道呈現
Weibull分佈之效能( 變動, )..............................52
圖4.7正交分頻多工系統工作於非頻選擇性衰落通道呈現
Weibull分佈之效能( 變動, )...............................53


表目錄

表2.1 資料傳輸率與Shift Keying 調變技術....................10

[1]R. W. Chang “Synthesis if Band-limited Orthogonal Signals Formultichannel Data Transmission,” BSTJ, vol. 46, pp. 1775-1796, Dec. 1966.
[2]Y. W. Cheong﹐R. S. Cheng﹐K. B. Lataief﹐and R. D. Murch﹐“Multiuser OFDM with Adaptive Subcarrier Bit and Power Allocation,” IEEE J. Selected Areas Comm.﹐vol.17﹐pp.1747-1758, Oct. 1999.
[3]S. Ben Slimane, Notes for Advanced Communication Theory, RoyaInstitute of Technology, Mar. 2002.
[4]Alan Triggs, Notes for Wireless, Cellular & Personal Telecommunications, Lecture 7, Southern Methodist University, Fal. 2001.
[5]Van Nee, R. & Prasad R., OFDM for Wireless Multimedia Communications, Artech House, Norwood, MA, 2000.
[6]Institute of Electrical and Electronics Engineers, 802.11a, Wire-less LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: High-Speed Physical Layer Extension in the 5 GHz Band, Sep. 1999.
[7]林千惠，張國安，”BFSK-OFDM訊號簡介及性能分析”， 無線電界， 43-65頁，July. 2000.
[8]Weinstein, S. B. , and P. M. Ebert, “Data Transmission by Frequency Division Multiplexing using the Discrete Fourier Transform,” IEEE Transactions on Communications, vol.19, Issue :5, pp.628-634, Oct. 1971.
[9]G. L. Turin, “Signal Design for Sequential Detection Systems with Feedback, “ IEEE Trans. Inform. Theory, vol. IT-11, pp. 401-408, Jul. 1965.
[10]B. Sklar, “Rayleigh Fading Channels in Mobile Digital Communication Systems Part 1: Characterization,” IEEE Trans. Commun., pp. 90-100, Jul. 1997.
[11]Matthias Pätzold, “Mobile Fading channel,” Wiley, pp.3-7, 2002.
[12]T. S. Rappaport, “Wireless Communications Principles and Practice.” Prentice Hall PTR, New Jersey, 1996.
[13]K. Bury, “Statistical Distribution in Engineering”, Cambridge, U.K：Cambridge Univ. Press, 1999.
[14]P. J. Crepeau, “Uncoded and Coded Performance of FSK and DPSK in Nakagami Fading Channels,” IEEE Trans. On Commun., vol. 40, No. 3, pp. 487-493, Mar. 1992.
[15]J. C. Lu and G.. K. Bhattaacharyya, “Some New Constructions of Bivariate Weibull Models,” Ann. Inst. Stat. Math, vol. 42, No.3, pp. 543-559, 1990.
[16]S. Kotz, N. Balakrishnan and N. L. Johnson, “Continuous Multivariate Distributions.” Vol. 1：Model and Applications, John Wiley and Sons, Inc, second ed., 2000.
[17]New York：Wiley, 2000.N. C. Sagias and G.. K. Karagiannidis, “Performance of Dual Selection Diversity in Correlated Weibull Fading Channels” M IEEE Tran. on Commun., vol. 52, No.7, pp. 1063-1067, Jul. 2004.
[18]L. Wan and V. K. Dubey, “BER Performance of OFDM System Over Frequency Nonselective Fast Ricean Fading Channels,” IEEE Commun.Lett., vol. 5, no. 1, pp. 19–21, Jan. 2001.
[19]J. G. Proakis, “Digital Communications.” 3rd ed., McGraw-Hill, New York, 1995.
[20]K. Dietze, C. B. Dietrich, and W. L. Stutzman, “Analysis of a Two-branch Maximal and Selection Diversity System with Unequal SNRs and Correlated Inputs for a Rayleigh Fading Channel,” IEEE Trans. Wireless Commun., vol. 1, pp. 274–281, Apr. 2002.
[21]Sklar, B., Digital Communications: Fundamental and Applications, 2nd ed. Prentice Hall, Upper Saddle River, NJ, 2001.
[22]Simon, M. K., and Alouini, M.-S., Digital Communication Over Fading channel 1st ed. John Wiley, New York, 2000.
[23]Y.-K. Ko, M.-S. Alouini, and M. K. Simon, “Average SNR of Dual Selection Combining over Correlated Nakagami-m Fading Channels,” IEEE Commun. Lett., vol. 4, pp. 12–14, Jan. 2000.
[24]Abu-Dayya, A.A., and Beaulieu, N.C.: “Analysis of switched diversity systems on generalized -fading channels,” IEEE Trans. Commun., vol. 42, pp. 1813–1831, Nov. 1994.
[25]Tellambura, C., Annamalai, A., and Bhargava, V.K.: “Unified Analysis of Switched Dversity Systems in Independent and Correlated Fading Channels,” IEEE Trans. Commun., vol. 49, pp. 1955–1965, Nov. 2001.
[26]H. Hashemi, “The Indoor Radio Propagation Channel,” Proc. IEEE, vol. 81, pp. 943-968, Jul. 1993.
[27]N. S. Adawi, H. L. Bertoni, J. R. Child, W. A. Daniel, J. E.Dettra, R. P. Eckert, E. H. Flath Jr., R. T. Forrest, W. C. Y. Lee,S. R. Mc Conoughey, J. P. Murray, H. Sachs, G. L. Schrenk, N.H. Shepherd and F. D. Shipley, “Coverage Prediction for Mobile Radio Systems Operating in the 800/900 MHz Frequency Range,” IEEE Transactions on Vehicular Technology, vol. 37, no. 1, pp. 3–72, Feb. 1988.
[28]A. Taneda, J. Takada, and K. Araki, “The Problem of the Fading model Selection,” IEEE Trans. Commun., vol. E84-B, no. 3, pp.355–358, Mar. 2001.
[29]Papoulis, “Probability, Random Variables, and Stochastic Processes, 3rd ed.” New York：Mcgraw-Hill, 1991.