(3.238.130.97) 您好!臺灣時間:2021/05/10 13:07
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:何建男
研究生(外文):Chien-nan Ho
論文名稱:三種使用最小移鍵訊號調變的直序分碼多重接收系統之性能比較
論文名稱(外文):Performance Comparison for Three DS-CDMA Systems Using MSK Modulation
指導教授:楊新雄楊新雄引用關係
指導教授(外文):Hsin-Hsyong Yang
學位類別:碩士
校院名稱:國立高雄第一科技大學
系所名稱:電腦與通訊工程所
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:2009
畢業學年度:97
語文別:中文
論文頁數:60
中文關鍵詞:直序分碼多重接收最小移鍵
外文關鍵詞:DS-CDMAMSK
相關次數:
  • 被引用被引用:0
  • 點閱點閱:157
  • 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
在本論文中,我們將探討最小移鍵(MSK)在三種直序展頻分碼多重接收(DS-CDMA)系統下的性能比較。在DS-CDMA系統下,因為許多使用者共用相同的頻帶,彼此之間互相干擾,當調變器為相位移鍵(PSK)時,且展頻碼接近正交狀況下,藉由先解展頻再解調變的方式,其他使用者的訊號也只會被當成雜訊,而不會產生嚴重的干擾。然而,若要使用連續相位調變(CPM)時,因為CPM本身具有的記憶性,造成先解展頻再解調變的方式法無法直接運用在CPM上,但是CPM中的MSK調變可以等效成為Filtered OQPSK,所以可以使用先解展頻再解調變的方式應用在DS-CDMA系統上。本文所探討的第一種方法為Lehnert[4]在1992年所建構,DS-CDMA-MSK系統以一種平行式(I-通道與Q-通道)的調變架構完成,在做直序展頻時,為了增加展頻碼的使用效益,使用同一個展頻碼中取出奇數與偶數的子碼來做為Q-通道跟I-通道的展頻碼,然而此種方法對消除干擾的效果極差。因此我們考慮第二種方法,同樣使用MSK的平行式架構,不同的是我們將I-通道跟Q-通道使用不同且獨立的展頻碼,讓DS-CDMA系統獲得更好的效能。第三種方法為Pawula[11]所提出的窄帶數位調頻技術-「鑑頻解調」。由於同調技術在無線通訊的環境下,接收機不易實現,因此我們討論MSK使用鑑頻解調在DS-CDMA系統下的效能。但經過鑑頻解調後得到的PAM訊號遭受到嚴重的破壞,所以就算使用先解展頻再解調變的方式也無法將其他使用者訊號造成的干擾濾除。
In this thesis, we will discuss performance comparison for three direct-sequence code division multiple access (DS-CDMA) systems using minimum-shift keying (MSK) modulation. In DS-CDMA system, as a result of multiple users to communicate simultaneously using the same frequency band, signals from different users will interfere with each other. As the DS-CDMA system using PSK modulation and the spread-spectrum code is approximately orthogonal, one can first apply despreading process and then follows with the demodulation process. In this way, the interference comes form other users can be rejected and can be considered as background noise. However, as the transmitted signals using continuous phase modulation (CPM), which have memory, the process of first despreading and then demodulation cannot be directly applied to DS-CDMA with CPM. However, a special form of CPM called MSK which can be considered as a filtered offset quadrature PSK. Due to the linear characteristic MSK, one can applying the first despreading and then demodulation process in DS-CDMA-MSK system. The first work was constructed by Lehnert [4] in 1991, where DS-CDMA-MSK system using a parallel two-channel (a quadrature channel and an in-phase channel) system. In order to increase the efficiency of spreading code, an odd number code and an even number code are extracted from a spreading code, and then applied to the Q-channel and I-channel as the spreading codes, respectively. But using these extracted spreading codes, the performance of using dispreading process to reject interference becomes worse. Therefore, we consider an alternative way by using parallel system with different orthogonal spreading codes for the Q-channel and I-channel, respectively. It is found the performance is much better than Lehnert’s system. Finally, we considered a noncoherent detection approach for DS-CDMA-MSK system, called limiter-discriminator detection. In [11], Pawula constructed a limiter-discriminator detection technology for narrow-band digital FM. It is shown that the received digital FM through limiter-discriminator becomes an equivalent spreading PAM signals. Nevertheless, using this detection approach for DS-CDMA-MSK, it is found that equivalent output PAM signals are mixed up with other user’s interference. It can not reject interference from other users by using the first despreading and then demodulation process. This thesis is concluded that by using two independent spreading codes for the I and Q channels respectively, one can effectively reject interference for multiple access systems using code division techniques.
中文摘要..................................................Ⅰ
英文摘要..................................................Ⅱ
誌謝......................................................Ⅳ
目錄......................................................Ⅴ
圖表目錄..................................................Ⅶ

第一章 序論
1.1 簡介.............................................1
1.2 研究動機.........................................2
1.3 論文架構.........................................3

第二章 直序分碼多重接收DS-CDMA系統之介紹
2.1 展頻系統之概念...................................4
2.2 展頻碼之原理與應用...............................6
2.3 直序分碼多重接收(DS-CDMA)之介紹..............12
第三章 平行式MSK模型在DS-CDMA系統下之探討
3.1 MSK訊號模型之介紹...........................15
3.2 平行式MSK傳送器與接收器之模型.................18
3.3 I、Q通道使用奇數、偶數展頻碼子碼之模型介紹........22
3.4 I、Q通道使用不同展頻碼之模型介紹.................27

第四章 MSK使用鑑頻解調器在DS-CDMA系統下之探討
4.1 窄帶數位FM模型................................30
4.2 雜訊統計........................................32
4.3 結合DS-CDMA系統..............................41

第五章 討論與結論........................................45

References................................................46
[1]R. E. Ziemer and R. L. Peterson, “Digital Communication and Spread Spectrum Systems,” New York :Macmillan, 1985.
[2]J. B. Andreson, T. Aulin, and C. –E. Sundberg. “Digital Phase Modulation” New York: Plenum, 1986.
[3]F. Amoroso and J. A. Kivett, “Simplified MSK signaling technique,” IEEE Trans. Commun., vol COM-25, pp. 433-441, Apr. 1977.
[4]J. S. Lehnert,“Serial MSK Spread-Spectrum Multiple-Access Communica-
tions,” IEEE Trans. Commun., vol. 40 pp. 1119 – 1127, June. 1992.
[5]B. Rimoldi, “Five views of differential MSK: A unified approach,” in communications and Criptography. Two sides of One Tapestry, R.Blahut, D. Kostello, U. Maurer, and T. Mittelholzer, Eds. New York: Kluwer, 1994.
[6]Z. Zvonar, “Performance of direct-sequence spread-spectrum systems using
continuous phase modulation,” in Proc. Mediterranean Electrotechnical Conf., 1989, pp. 520–523.
[7]陳曉華,【展頻與分碼多工通訊理論-數位行動通訊叢書】,2004 全華科技圖書公司, ISBN-957-21-4411-1.
[8]D. E. Cartier, “Limiter-discriminator detection performance of Manchester and NRZ coded FSK, ”IEEE Trans. Aerosp. Electron. Syst., vol. AES-13, PP. 62-70, Jan. 1977.
[9]J. E. Mazo and J. Salz, “Theory of error rates for digital FM, ”Bell Syst. Tech. J., vol. 45, pp.1511-1535, Nov. 1966.
[10]M. K. Simon and C. C. Wang, “Differential versus limiter-discriminator detection of narrow-band FM, ” IEEE Trans, Commun., vol. COM-31, pp.1227-1234, Nov 1983.
[11]R. F. Pawula, “On the theory of error rates for narrow-band digital FM, ”IEEE Trans. Commun., vol. COM-29, pp. 1634-4643, Nov. 1981.
[12]R. F. Pawula, S. O. Rice, and J. H, Roberts, “Distribution of the phase angle between two vectors perturbed by Gaussian noise, ”IEEE Trans. Commun., vol. COM-30, pp. 1828-1841, Aug. 1982.
[13]T. T. Tjhung and P. H. Wittke, “Carrier transmission of binary data in a restricted band,” IEEE Trans. Commun Technol., vol. COM-18, pp. 295-304, Aug. 1970.
[14]J. G. Proakis, “Digital Communications,” 4th ed., New York: McGraw-Hill, 2001.
[15]S. Haykin, “Digital Communication Techniques,” Englewood Cliffs, N.J :
PTR Prentice Hall, 1994.
[16]B. Sklar, “Digital Communication : Fundamentals and Applications,” 2th ed., Los Angeles: Prentice Hall, 1994.
[17] K. Feher, “MODEMS for Emerging Digital Cellular-Mobile Radio System,” IEEE Trans.Vehicular Technol., vol. 40, pp. 355-365, May. 1991.
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