臺灣博碩士論文加值系統

本篇論文架構於跳時（time-hopping）脈波位置調變（PPM）之超寬頻（UWB）脈波無線電（IR）通訊系統，主要分成多用戶檢測及盲蔽式信號接收兩部分。本文提出數種線性多用戶檢測器，在頻率選擇性衰減通道，對多用戶存取干擾（MAI）進行有效抑制，順利的擷取出目標資訊位元。而後我們發展出了兩種低複雜度的行動台（MS）接收機。其中一種乃源自於傳統的耙式接收機(RAKE receiver)，另一種則是為了最小化輸出功率（minimum output energy, MOE）的目標而設計。然而這兩種接收機均須仰賴精確的通道估計，因此我們便推演出了一種盲蔽式（blind）的通道估計法則，同時針對幾個可能有關因子，分析通道估計準確度的相對影響。而由驗證分析的部分可發現，兩種接收機不僅改善了遠近（near-far）效應、多用戶存取干擾問題，同時對於系統效能亦有所增益。

This thesis is based on time-hopping (TH) pulse position modulation (PPM) in Ultra-Wideband (UWB) impulse radio (IR) communication system, and mainly divides into two parts：multiuser detection and blind interference suppression. We apply a class of linear multiuser detectors (LMDs) to extract the information bits while suppress multi-access interference (MAI) even in the presence of multipath fading. Morever, we develop two types of low-complexity mobile station (MS) receivers. One is originated from the conventional RAKE receiver and the other is designed to meet the minimum output energy (MOE) criterion. However, since accurate channel information is crucial for reliable operation, thereby we propose a blind (non-data aided) channel estimator. The numerical and analytical results demonstrate that not only multi-access interference and near-far problem can be suppressed effectively but also system performance is comprehensively improved.

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.............................................................ix
表目錄.............................................................xi

第一章 緒論.........................................................1
1.1研究動機.................................................. 1
1.2研究方法...................................................2
1.3內容大綱...................................................2
第二章 UWB通訊系統...................................................3
2.1 UWB之定義................................................3
2.2 UWB IR通訊系統特性........................................6
2.3 UWB的應用...............................................10
2.4訊號模型.................................................12
2.5衰減通道.................................................14
2.6接收端訊號模型............................................16

第三章 線性多用戶檢測器.............................................18
3.1 BPPM TH-UWB之線性多用戶檢測器............................18
3.1.1傳統線性多用戶檢測器................................24
3.1.2解相關檢測器.......................................26
3.1.3線性最小均方誤差檢測器..............................27
3.2數值分析與效能評估........................................28
第四章 下鏈跳時超寬頻系統之盲蔽式信號接收.............................33
4.1 Direct processing receiver (架構一).....................34
4.1.1 Maximum-ratio-combining(MRC) receiver............36
4.1.2 Minimum-output-energy(MOE) receiver..............37
4.2 Despreading-Combining receiver (架構二).................39
4.2.1 MRC receiver.....................................44
4.2.2 MOE receiver.....................................45
4.3盲蔽式通道估計演算法.......................................46
4.4實際情況.................................................49
4.4.1架構一之實際情形....................................50
4.4.2架構二之實際情形....................................52
4.5數值分析與效能評估........................................54
4.5.1通道估計之準確度分析.................................54
4.5.2 Direct processing receiver分析....................58
4.5.3 Despreading-Combining receiver分析................62
第五章 結論.......................................................65
參考文獻............................................................67

[1]M. Z. Win and R. A. Scholtz, “Ultra wide bandwidth time-
hopping spread-spectrum Impulse Radio for wireless multiple
access communications,” IEEE Trans. on Communications, vol. 48,
no. 4, pp. 679-691, Apr. 2000.
[2]M. Z. Win, R. A. Scholtz and M. A. Barnes, “Ultra-wide bandwidth
signal propagation for indoor wireless multiple access
communications,” Proc. IEEE Int. Conf. Communications, vol. 1,
Montreal, Canada, Jun. 1997, pp. 56-60.
[3]M. Z. Win and R. A. Scholtz, “On the robustness of ultra-wide
bandwidth signals in dense multipath environments,” IEEE Commun.
Lett., vol. 2, pp. 51-53, Feb. 1998.
[4]M. L. Welborn, “System considerations for ultra-wideband wireless
networks,” IEEE Radio and Wireless Conference, pp. 5-8, 2001.
[5]M. Z. Win and R. A. Scholtz, “Impulse radio: How it works,” IEEE
Communications Letters, vol. 2, no. 1, Jan. 1998.
[6]R. A. Scholtz, “Multiple access with time-hopping impulse
modulation,” Proc. MILCOM’93, vol. 2, pp. 447-450, 1993.
[7]F. R. Mireles, “Performance of ultrawideband SSMA using time
hopping and M-ary PPM,” IEEE J. Select. Areas Commun., vol. 19,
no. 6, pp. 1186-1196, Jun. 2001.
[8]L. Zhao and A. M. Haimovich, “Multiuser capacity of M-ary PPM
ultra-wideband communications,” 2002 IEEE Conference on Ultra
Wideband Systems and Technologies, pp. 175-179.
[9]B. Hu and N. C. Beaulieu, “Precise bit error rate of TH-PPM UWB
systems in the presence of multiple access interference,” IEEE
Conference on Ultra Wideband Systems and Technologies, pp. 106-
110, 2003.
[10]N. Boubaker and K. B. Letaief, “Ultra wideband DSSS for multiple
access communications using antipodal signaling,” IEEE
International Conference on Communications, pp. 2197-2201, May
2003.
[11]Y. Shin, H. Lee, B. Han,and S. Im, “Multipath characteristics of
impulse radio channel,” Proc. Vehicular Technology Conference,
pp. 2487-2491, Boston, Oct. 2000.
[12]M. Ghavami, Ultra wideband signals and systems in communication
engineering, John Wiley & Sons, Inc., 2004.
[13]R. Price and P. E. Green, “A communication technique for
multipath channel,” Proceedings of the IRE, pp. 555-570, Mar.
1958.
[14]M. L. Honig, U. Madhow, and S. Verdu, “Blind adaptive multiuser
detection,” IEEE Trans. on Information Theory, vol. 41, no. 4,
pp. 944-996, Jul. 1995.
[15]R. O. Schmidt, “Multiple emitter location and signal parameter
estimation,” IEEE Trans. Ant. Propagation, Vol. AP-34:276-290,
March 1986.
[16]H. Liu and G. Xu, “A subspace method for signature waveform
estimation in synchronous CDMA systems,” IEEE Trans. Commun.,
Vol. COM-44, No. 10, pp. 1346-1354, Oct. 1966.
[17]FCC, “Revision of Part 15 of the Commission’s Rules Regarding
Ultra-Wideband Transmission System,” First Report and Order, ET
Docket pp.98-153, Feb. 2002.
[18]C. Fowler, J. Entzminger, J. Vorum, “Report: Assessment of Ultra-
Wideband Technology,” OSD/DARPA Ultra-Wideband Rader Review
Panel, R-6280, 1990.
[19]Gian Mario Maggio, “An introduction to UWB,” CWC/UCSD &
STMicroelectronics, Dec. 2002.
[20]R. Fisher et al., “DS-UWB Physical Layer Submission to 802.15
Task Group 3a,” IEEE 802.15-04/0137r3, Motorola, Inc. et al.,
Jul. 2004.
[21]A. Batra et al., “Multi-band OFDM Physical Layer Proposal,”
IEEE 802.15-03/267r6, Texas Instruments et al., Sept. 2003.
[22]A. Batra et al., “MultiBand OFDM Physical Layer Proposal for
IEEE 802.15 Task Group 3a” MBOA-SIG, Sept. 2004.
[23]J. Foerster, E. Green, S. Somayazulu, and D. Leeper, “Ultra-
Wideband Technology for Short- or Medium-Range Wireless
Communications,” Intel technology Journal, Q2, pp. 1-11, 2001.
[24]Porcino, D.; Hirt, W., “Ultra-Wideband Radio Technology :
Potential and Challenges Ahead,” IEEE Communication Magazine,
Jul. 2003.
[25]S. Verdu. Multiuser Detection, Cambridge University Press, 1998.
[26]S.M.Kay, “Fundamental of Statistical Processing: Vol.I –
Estimation Theory,” Prentice Hall, 1993 pp.390-391.
[27]H. L. Van Trees, Optimum Array Processing, John Wiley & Sons,
Inc., 2002.
[28]M. Torlak and G. Xu, “Blind multiuser channel estimation in
asynchronous CDMA systems” IEEE Trans. Signal Processing, vol.
45, pp.137-147, Jan. 1997.
[29]T. K. Moon and W. C. Stirling, Mathematical Methods and
Algorithms, Prentice-Hall, Inc. 2000.
[30]Jun Wu ,Yi Wang and K.K.M Cheng, “Blind channel estimation based
on subspace for multicarrier CDMA” IEEE Vehicular Technology
Conference, Vol. 4, No. 6-9, pp. 2374 - 2378, May 2001.
[31]Wei Sun and Hongbin Li., “Blind channel identification for
multicarrier CDMA systems with transmit diversity” IEEE
Communications, Vol. 2 , No. 28, pp. 727-731, May 2002.
[32]T. U., K. D. and L., H. “Channel estimation for multicarrier
CDMA” IEEE, Acoustics, Speech, and Signal Processing, Vol.5,
No.5-9, pp. 2909 – 2912, June 2000.
[33]Tureli, U.; Kivanc, D. and Liu, H., “Channel estimation
for multicarrier CDMA,” IEEE Acoustics, Speech, and Signal
Processing, Vol. 5 , No. 5-9, pp. 2909 - 2912, Jun. 2000.