臺灣博碩士論文加值系統

摘要
本篇論文中，我們考慮GSM/DCS-1800 空間分隔多工(SDMA)無線通訊環境，進一步分析了GMSK訊號在多通道路徑衰減環境下利用Viterbi 等化器將資料還原之平均位元錯誤率。我們也使用智慧型天線陣列技術來解決通道衰減(fading) ，及多重路徑的影響。在GSM 真實系統中通常考慮三種不同的通道模型，即城市(Typical Urban, TU)，鄉村(Rural Area, RA)，山區，丘陵(Hilly Terrain, HT) 經由電腦模擬得知，在原本單一天線接收的困頓情況下，加入空間-時間處理技術可有效改善系統效能及容量。
由實驗中我們可發現，在兩種不同的通道估測中(Least square及Correlation estimator)在相同的BER下，前者的性能較後者優越約3dB。在天線方面，也可看出在相同的SNR下一根天線的錯誤率約為四根天線的1000倍左右。

Abstract
In this thesis, we consider the GSM space-division multiple access in mobile wireless communication, we analyzes the average bit error rate of GMSK signal using Viterbi equalizer to recover data in multi-path fading environment. We also use the technique of smart antenna array in the GSM/DCS-1800 to solving the affecting of channel fading, multi-path fading. We usually consider different type of channel model in the real GSM system, which are typical urban (TU), rural area (RA), and hilly terrain (HT). By the computer simulations, we know that we can improve the bad receive situation as well as increase the efficiency and capacitance of system by replace the single antenna system with the one added the space-time process technique.
By the computer simulations, we know at the same BER, the least square estimator is better than the correlation estimator about 3dB above. And at the same SNR, one antenna is about 1000 times the BER of four antennas.

CONTENTS
PAGE
ABSTRACT (IN CHINESE) V
ABSTRACT (IN ENGLISH) VI
ACKNOWLEDGMENTS VII
CHAPTER 1 INTRODUCTION 1
1.1 The communication system 1
1.2 Digital and analog communications 2
1.3 One of discrete-time models for a channel with ISI 3
1.4 Thesis structure 5
CHAPTER 2 MOBILE RADIO COMMUNICATION
SYSTEM CHANNEL EQUALIZATION 6
2.1 Baseband transmission system 6
2.1.1 BER of baseband system 8
2.2 Characterization of fading channels 9
2.2.1 Type of small-scale fading 9
2.2.2 Flat fading 11
2.2.3 Frequency selective fading 11
2.2.4 Fast fading 12
2.2.5 Slow fading 13
2.3 Rayleigh fading distribution 13
2.4 Ricean fading distribution 14
CHAPTER 3 VITERBI EQUALIZER FOR GMSK
SIGNAL 15
3.1 Principle of Viterbi algorithm 15
3.2 Baseband modulation of GMSK 19
3.3 Principe analysis of Viterbi equalizer 25
3.3.1 Sounding sequence 26
3.3.2 Channel estimation and windowing 29
3.3.2.1 Channel estimation 29
3.3.2.2 Channel windowing 31
3.3.3 Estimated signal generation 33
3.3.4 Ambiguity function 34
3.3.5 Incremental metric calculator 36
3.4 Viterbi equalization of GMSK signal 37
3.5 Some existing methods using adaptive smart
antenna arrays 41
3.5.1 Time-only processing 42
3.5.2 Space-only processing 43
3.5.3 Space-time processing 44
CHAPTER 4 COMPUTER SIMULATIONS 48
4.1 System parameter of GMSK/DCS1800 48
4.2 Channel model 49
4.3 Computer simulations 50
CHAPTER 5 CONCLUDING REMARKS AND
FUTURE RESEARCH WORK 59
5.1 Conclusion 59
5.2 Suggestion for future research 59
REFERENCES 61

REFERENCES
[1] T. S. Rappaport, Wireless Communications Principles and Practice. New Jersey: Prentice Hall PTR, 1996.
[2] S. Haykin, Communication System, 3rd ed. New York: John Wiley & Sons, INC, 1994.
[3] J. B. Anderson, T. Aulin, and C.E. Sundberg, Digital Phase Modulation. New York: Plenum Press, 1986.
[4] J. G. Proakis, Digital Communication, 3rd ed. New York: McGraw-Hill, Inc, 1995.
[5] R. Stell, Mobile Radio Communication. New York: IEEE press,1992.
[6] K. Feher, Wireless Digital Communication Modulation & Spread Spectrum Application. New Jersey: Prentice Hall PTR, 1995.
[7] K. Feher, Digital Communication: Satellite/Earth Station Engineering. Englewood Clifss, NJ: Prentice Hall, Inc, 1983.
[8] S. O. Rice, "Mathematical analysis of random noise," Bell Systems Technical Journal, Vol. 23, pp. 282-332, July, 1944.
[9] G. D. Forney, Jr., "Error bounds for convolutional codes and an asymptotically optimal decoding algorithm," IEEE Trans. Inform. Theory., vol. 13, pp. 260-269, Apr. 1967.
[10] A. Gorokhov, "On the performance of the Viterbi equalizer in the presence of channel estimation errors," IEEE Signal processing letters., vol. 5, pp. 321-324, Dec. 1998.
[11] J. G. Proakis, Digital Communication, 2nd ed. New York: McGraw-Hill, Inc, 1989.
[12] J. B. Anderson, T. Aulin, and C.E. Sundberg, Digital Phase Modulation. New York: Plenum Press, 1985.
[13] G. D. Forney, Jr, "The Viterbi algorithm," Proc. IEEE, vol.61, No. 3, pp. 268-278 March, 1973.
[14] R. Steele and I. J. Wassell, Mobile Radio Communication. London: Pentech Press Publishers, pp.523-597, 1992.
[15] A. Mehrotra, GSM system Engineering. Boston, London: Artech House, Inc., pp. 78-81, 1996.
[16] J. H. Winters "Smart antennas for wireless systems" IEEE Personal Communications Mag., pp. 23-27, 1998.
[17] W. C. Jakes, Microwave mobile communications. New York: Wiley, pp. 66-70, 1974.