本論文主要探討在多重使用者的合作式網路(cooperative networks)中的夥伴選擇(partner selection)機制，網路中的合作夥伴使用中繼協定中的編碼合作(coded cooperation)來傳送資訊，有集中式夥伴選擇(Centralized Partner Selection)跟分散式夥伴選擇(Distributed Partner Selection)這兩種策略來找適合的中繼點，集中式夥伴選擇的夥伴配對較分散式夥伴選擇易達到整體的最佳化，但是集中式夥伴選擇的複雜度很高，且整體通道資訊的取得需耗費大量的無線資源，尤其當使用者增加的時候，找尋適合的中繼點所需的成本大幅增加，所以我們改採用分散式夥伴選擇來尋找適合的中繼點。分散式夥伴選擇裡的固定優先權選擇演算法是根據使用者的編號，以固定的規則替所有使用者分配相同數目的夥伴。但由於使用者編號並不包含任何通道相關資訊。這篇論文主要是要利用使用者的位置資訊，使分散式夥伴選擇達到更好的效能，而與分散式夥伴選擇比較不同的是，本篇論文採用載波偵聽多路存取(Carrier Sense Multiple Access, CSMA)原理方式，讓使用者可以知道其他使用者的更多的通道相關資訊，所以提出了涵蓋搜索演算法(Coverage Search Algorithm)，最近點搜索演算法(Nearest Source Search Algorithm)，最近中點搜索演算法(Nearest Middle-Point Search Algorithm)這三個演算法。本篇論文的貢獻在於提高了在分散式夥伴選擇中的訊雜比(signal to noise ratio, SNR)，使得可達容量(achievable rate)大於資料速率(data rate)的機率大大提昇，也降低了整個系統的中斷率，增加了整個系統的性能。

In this thesis, we investigate partner selection schemes in multiuser cooperative networks. In networks, cooperative partners adopt coded cooperation to forward signals. Among the literature, two classes of two namely, centralized partner selections and distributed partner selections, have been proposed to select appropriate relays. Centralized partner selection is able to achieve the global optimization than distributed partner selection. However, centralized partner selections require high complexity, and global channel state information, which demands large amount of overhead and waste radio resources. Especially when the size of network increases, the cost to search appropriate relay for each user dramatically increases. Hence, we consider distributed partner selection scheme in the thesis. Among the existing work, fixed priority selection algorithm is a distributed partner selection algorithm strategy; where partner assignment is based on node indices do not include any channel information. To enhance performance, we exploit the geographical information of all users. Different from other distributed partner selection schemes, we adopt the method of Carrier Sense Multiple Access to exchange local information. We proposed coverage search algorithm, nearest source search algorithm and nearest middle-point search algorithm, the serve as the criteria of partner selection. The contributions of this thesis are to raise SNR, increase the probability that the achievable rate is great than the data rate in the distributed partner selection scheme, and enhance system performance.

致謝 i
Abstract iii
摘要 iv
目錄 v
圖目錄 vii
表目錄 ix
第一章 簡介 1
第二章 相關背景 5
2.1背景. 5
2.2相關文獻.. 6
2.2.1編碼合作.. 6
2.2.2集中式夥伴選擇 7
2.2.2.1最小化最大演算法 7
2.2.2.2匹配演算法 8
2.2.3分散式夥伴選擇 9
2.2.3.1隨機選擇演算法 9
2.2.3.2接收訊雜比選擇演算法 11
2.2.3.3固定優先權選擇演算法 13
第三章 系統模型. 17
3.1 單一中繼點之編碼合作 17
3.2 通道模型:任二節點之傳輸之訊雜比 19
3.3 多重使用者之合作式網路 20
第四章 夥伴選擇 24
4.1 涵蓋搜索演算法 26
4.2 最近點搜索演算法 27
4.3 最近中點搜索演算法 29
第五章 模擬結果和比較 32
第六章 結論 42
參考文獻 43

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