下行多載波分碼多重存取系統之用戶分組與適應性調變機制

User Grouping and Adaptive Modulation for Downlink MC-CDMA Systems

沈冠毅(Guan-Yi Shen)

指導教授 ： 郭耀文

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2009年)

https://doi.org/10.6837/NCNU.2009.00272

摘要

本論文中提出在下行多載波分碼多重存取 (Multi Carrier-Code Division Multiple Access，簡稱MC-CDMA)系統中的用戶分組與適應性調變機制。在頻率選擇性衰減通道下，根據通道狀態資訊(channel state information)將用戶分配至衰減較小的群組後，可以增加系統頻譜效率與降低系統位元錯誤率。在用戶分組後，每位用戶依據通道狀態資訊調整所使用的調變與功率，讓基地台(Base station)在有限的傳送功率下能最大化系統的傳輸量，同時也能根據每位用戶的位元錯誤率門檻，讓所有用戶達到預期的位元錯誤率。比較本論文與參考文獻機制後，模擬結果顯示此論文在位元錯誤率與系統傳輸量皆優於參考文獻。

關鍵字

多載波分碼多重存取 ； 下行 ； 用戶分組 ； 適應性調變

並列摘要

In this thesis, we propose a user grouping and adaptive modulation algorithm for downlink Multi-Carrier Code Division Multiple Access (MC-CDMA) systems. Under a frequency-selective fading channel, we adaptively classify users into groups by their channel state information (CSI) such that spectrum efficiency is improved and BER is reduced. After grouping, we assign bit loading and allocate transmission power for each user according to its effective channel response. Our scheme aims at maximizing total system data rate under the total power and users’ BER constraints. We also compare the performance of our scheme with the reference papers, and simulation results show that our scheme outperforms at bit error rate and data rate.

並列關鍵字

MC-CDMA ； downlink ； user grouping ； adaptive modulation

參考文獻

[1] N. Yee, J. P. Linnartz and G. Fettweis, “Multi-Carrier CDMA in Indoor Wireless Radio Networks,” Proceedings PIMRC ’93, Yokohama, pp. 109-113, Japan, 1993.

[2] C. Tang and V. J. Stolpman, “Multiple users adaptive modulation schemes for MC-CDMA,” in Proc. IEEE GLOBECOM, pp. 3823–3827, Dec. 2004.

[3] S. Hara and R. Prasad, “Overview of multicarrier CDMA,” IEEE Commun. Mag., vol. 35, pp. 126–133, Dec. 1997.

[4] Seong Taek Chung, and A. J. Goldsmith, “Degrees of freedom in adaptive modulation: a unified view,” IEEE Transactions on Communication, vol. 49, pp. 1561-1571, Sep 2001.

[5] Jinri Huang and Zhisheng Niu,“A Fairness-based and Adaptive User Grouping and Subcarrier Allocation Algorithm for Grouped MC-CDMA Systems”,IEEE GLOBECOM '06 Global Telecommunications Conference, pp. 1-5, Dec. 2006.