跳躍減低合作式架構下利用階層調變進行虛擬多天線系統之效能分析

performance analysis based on hop-reduced cooperative scheme by using hierarchical modulation in MIMO system

王舜弘(Shuen-Hung Wang)

指導教授 ： 吳靜雄

共同指導教授 ： 李揚漢

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10831

摘要

合作式傳輸系統 ( Cooperative communication )可以帶來許多好處，例如可以增加系統的傳輸容量，也可以增加基地台與行動裝置的通訊範圍，並且在LTE-Advanced與WiMAX都已將合作式傳輸作為改善細胞邊緣 ( Cell edge ) 傳輸效能以及擴展傳輸範圍的一個方案。
在傳統的中繼節點 ( Relay node ) 設計，行動裝置與基地台間的傳輸必須執行一次以上的跳躍 ( Hop )，整體的傳輸速率會因此而下降。利用階層式調變 ( Hierarchical modulation )與空時區塊碼 ( Space time block code ) 的結合，讓中繼節點來獲得額外的資料，來實現跳躍減低的合作式空時區塊碼，
在中繼節點設計方面，本論文提出利用中繼節點來當作虛擬天線，當行動裝
置位於細胞邊緣，可以啟動合作式傳輸，配合行動裝置的編碼，可以讓基地台得到高維度的空間多樣性，使系統的位元錯誤率下降。並且利用模擬結果，可以估算中繼節點對於基地台與行動裝置之間的距離，提供涵蓋範圍的大小，以供配置中繼節點的參考依據。
此篇論文貢獻在於 (1) 提出在先進的長期演進( LTE-Advanced )的規範下，一種行動裝置與中繼節點間的編碼，利用此編碼，可以讓基地來得到高維度的多樣性。 (2) 有效的縮減行動裝置的天線數，有效的降低系統設計的複雜度、成本以及功率。

關鍵字

合作式傳輸 ； 中繼節點 ； 階層式調變 ； 多輸入多輸出 ； 廣義存取節點

並列摘要

A cooperative communication system can bring many advantages. Not only does the cooperative system increases transmission capacity, but also expands communication coverage between the base station and the mobile station. Further, Long Term Evolution Advanced (LTE-A) and Worldwide Interoperability for Microwave Access (WiMAX) are both regarded as cooperative technologies designed to improve the transmission rate at cell edge and broaden transmission coverage.
In the traditional relay node design, data transmission must jump at least one time between the mobile station and the base station. It is generally noticed that overall transmission rates might be decreased since the base station should receive the decodable compositions of symbols from the mobile station and the relay node. One proven method in solving this problem has been combining hierarchical modulation and space time block code, in which case the relay node gets additional data information from the source.
This thesis proposes a ‘decode-and-forward’ type based cooperative technique which will make at transmitting and receiving at the same time possible. When the mobile station locates in cell edge, cooperative communication is started for high order spatial diversity. By using this cooperative technique, the relay node can be regarded as another transmission antenna from the mobile station. Eventually, the base station has lower bit error rate after the proposed cooperation mode is employed. Moreover, we can estimate the distance between the relay node and the mobile station and the relay node and base station. After then, we can provide coverage references to building a relay node.
The contribution of this thesis includes (1) a space time block code for the mobile station and the relay node (following the LTE-A and WiMAX standard) that can let the base station have high order transmission diversity. (2) a decrease in the number of transmission antennas in the mobile station and the complexity, cost and power for the system.

並列關鍵字

Cooperative communication ； Relay node ； Hierarchical modulation ； MIMO ； General access node

參考文獻

[1] Y.-H. Lee, “LTE MIMO system design considerations toward IMT-Advanced 4G,” Department of Electrical Engineering, Tamkang University, Feb. 2010.

[2] W.-C. Li, “Carrier frequency offset detection by applying hierarchical modulation for OFDM communications,” M.S. thesis, National Taiwan University, June 2010.

[3] “MIMO,” Wikipedia, March 2011.http://zh.wikipedia.org/wiki/MIMO

[4] K.-C. Loa, C.-C. Wu, S.-T. Sheu, Y.-F. Yuan, M. Chion, D. Hou, and L. Xu. “IMT-advanced relay standards,” IEEE Commun. Mag., vol. 48, no. 8, pp.40-48, August 2010.

[5] K.-C. Loa, “IMT-advanced relay,” Institute for Information Industry, June 2010.