臺灣博碩士論文加值系統

無線通到由於受到多路徑干擾的影響而有嚴重的衰減。使用時間或頻率分集為有效減緩衰減的技術；然而在多數情形下，無線通到為緩慢變化與頻率非選性，因此利用天線分集成為比較實用的技術。多重輸入多重輸出系統除了能夠經由空間分集來抵抗通道衰減，同時也能夠增加系統的的容量。這些發現引發了時空碼的研究，時空碼結合了通道編碼與多傳輸天線設計而能有效應用於多路徑干擾之無線通道。
　　藉由結合多階層編碼的設計與時空區段碼子集分割的概念，我們提出了一項多階層時空區段碼的新技術。利用多層解碼演算法可以得到較低之複雜度，獲得近似最佳性能。

The multipath wireless channel suffers severe attenuation. The effective techniques to mitigate multipath fading are time and frequency diversity. In most situations, the wireless channel is slow varying and frequency non-selective. Hence, antenna diversity is a practical technique for reducing the effect of multipath fading. Multiple input multiple output wireless channels can introduce spatial diversity and increased information capacity. These results have motivated a new area in error correcting codes. Space-time codeing(STC) schemes combine the channel code design and the use of multiple transmit antennas.
With combining Multi-level coding technique and set partition of space-time block code set, We will propose a novel design of space-time block codes. Using Multi-level coding technique can get lower complexity and the better performance.

目 錄
摘要………………………………………………………………………I
Abstract ………………………………………………………………..Ⅱ
致謝……………………………………………………………………..Ⅲ
目錄……………………………………………………………………..Ⅴ
圖表索引………………………………………………………………..Ⅶ
第一章 緒論……………………………………………………………..1
第二章 時空區段碼……………………………………………………..3
2-1 分集 ………………………………………………………….4
2-1.1 時空分集(Temporal Diversity)………………………4
2-1.2頻率分集(Frequency Diversity)………………………4
2-1.3 空間分集(Space Diversity) ………………………….5
2-2 時空區段碼系統模型………………………………………...5
2-2.1 時空區段編碼………………………………………..6
2-2.2 時空區段解碼………………………………………..6
2-3 Alamouti Scheme……………………………………………...7
2-4 設計理論……………………………………………………...9
2-5 時空區段編碼與正交矩陣設計…………………………….13
2-5.1 時空區段編碼與實數正交方陣……………………13
2-5.2時空區段編碼與一般化實數正交矩陣…………….14
2-5.3時空區段編碼與複數正交矩陣…………………….15
第三章 多階層時空區段碼設計………………………………………19
3-1 多階層時空區段編碼調變………………………………….19
3-2 計算最小距離……………………………………………….21
3-3 多階層時空區段解碼……………………………………….23
3-4 模擬結果…………………………………………………….28
第四章 結論……………………………………………………………30
Reference……………………………………………………………….31
附錄……………………………………………………………………..33
作者簡介………………………………………………………………..34

圖表索引
圖2.1 時空區段碼系統模型………………………………………….5
圖2.2 Alamouti 時空區段編解碼架構………………………………7
圖2.3 多傳輸天線比較………………………………………………16
圖3.1 多層區段編碼調變方塊圖……………………………………19
圖3.2 QPSK sympol and ……………………………………20
圖3.3 圖3.3 多階層時空區段碼編碼方塊圖……………………….21
圖3.4 set partition…………………………………………………….23
圖3.5 四層區時空區段編碼解碼方塊圖……………………………27
圖3.6 decoding Trellises……………………………………………...28
圖3.7 模擬結果………………………………………………………29

[1] G..J .Foschini and M . J. Gans, “On limits of wireless communications in a fading environment when using multiple antennas. ”Wireless. Pres. Commun . vol6 ,pp .311-335,Mar. 1998

[2] I. E.Telatar,”Capacityof multi-antenna gaussianchannels ”Eur. Trans. Telecommun ,vol0,no.6 ,pp.585-595,Nov.1999.

[3] V. Tarokh, N.Seshadri and A. R. Calderbank , ” Space-time Codes for high data rate wireless communication performance Criterion and code construction, ”IEEE. Trans. Inform. Theory, vol44,pp.744-765,Mar. 1998

[4] S.Almouti “A simple transmit diversity technique for wireless communications ”IEEE J. Select Areas Commun. , vol. 16, pp.1451-1458, Oct. 1988.

[5] D. Agrawal, V. Tarokh, A. Naguib, and N. Seshadri, “Space–time coded OFDM for high data-rate wireless communication over wide-band channels,” in Proc. IEEE Vehicular Technolgy Conf.,Ottawa, ON, Canada, May 1998, pp. 2232–2236.

[6] Y. Li, N. Seshadri, and S. Ariyavisitakul, “Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels,”IEEE J. Select. Areas Commun., vol. 17, pp. 461–471, Mar.1999.

[7] Y. Li, J. Chuang, and N. Sollenberger, “Transmitter diversity for OFDM systems and its impact on high-rate data wireless networks,”IEEE J. Select. Areas Commun., vol. 17, pp. 1233–1243, July 1999.

[8] A. Naguib, N. Seshadri, and A. Calderbank, “Increasing data rate over wireless channels,” IEEE Signal Processing Mag., vol. 17, pp.76–92, May 2000.

[9] V. Tarokh, H. Jafarkhani, and A. R. Calderbank, “Space-Time Block Coding for Wireless Communications: Performance Results, ” IEEE J. Select Areas Commum., vol. 17, pp.451–460, March 1999.

[10] H. Jafarkhani, and N. Seshadri, “Super-Orthogonal Space-Time Trellis Codes, ” IEEE Trans. Inform. Theory, theory, vol 49, pp937–950, April 2003.

[11] H. Imai and S. Hirakawa, “A New Multilevel Coding Method Using Error-Correcting Codes,” IEEE Trans. Inform. Theory, 23(3), pp.371-376, May 1977.