在本篇論文中我們討論一種在雙向中繼網路(Two-Way Relay Network, TWRN)下做分散式中繼點選擇的方法，大多論文探討TWRN架構裡來源端(Source)到中斷點(Relay)的通道與中繼點到來源端的通道是相互惠(Reciprocal)，在來源端可以塞入領航訊號(Pilots)的方式來得到各自到中斷點的通道狀態資訊(Channel State Information, CSI)，而在通道相互對稱情況下，中斷點反饋(Feedback)通道資訊回來源端，由於通道相互對稱來源端也可以得到中繼點回傳來源端這段通道，進而來源端可以得到全部通道的資訊，在之後中斷點的選擇可以由任何一個端點來做判斷，來達到全多樣性(Full Diversity)，然而來源端可以估得所有通道資訊情形並不適用在非對稱通道下，是由於來源端即使塞入領航訊號仍然不能獲得所有通道資訊，而在通道資訊不齊全的情況下端點來做選擇，會喪失部分的多樣性。為了解決來源端會缺少部分通道資訊的情況，我們提出了一種分散式中斷點選擇的方式，我們利用由兩個端點來做判斷，讓來源端彼此彌補各自缺少的通道，利用這種分散式選擇的方式，不需要將通道資訊傳到中央，再由中央來選擇這種需要耗費大量資源的方式，進而提高效能也能達到全多樣性，最後我們利用電腦模擬來驗證我們所提出的方法，並由我們所分析所得到的中斷機率與電腦模擬做比較可以發現兩者的效能是相當接近的，也近一步證明我們分析方式的正確性。

The relay selection problem in two-way relay network is considered in this study. Previous work use one of the source node as a central to select relay in symmetric TWRN. But relay selection with central node in asymmetric two-way relay networks may not be a proper assumption because which needs to forward some instantaneous channel information from one source node to the other. To solve this problem, we propose a distributed selection scheme to enhance the performance and achieve full diversity. Simulation results show the effectiveness of the proposed scheme.

誌謝 ii
中文摘要 iii
Abstract iv
目錄 v
圖目錄 vi
第一章 導論 1
1.1研究動機 2
1.2論文架構 2
第二章 TWRN系統架構 3
第三章 基於TWRN下之中繼點選擇方法 10
3.1 Opportunistic relay selection 10
3.2 MRC 19
第四章 Distributed Relay Selection 23
第五章 模擬結果 38
5.1 在各種不同條件下的模擬結果分析 38
5.2 Distributed Relay Selection 40
第六章 結論 43
參考文獻 44
中英對照表 50
縮寫對照表 54

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