在此篇論文中，我們是考慮當通道係數未知，以放大前送(Amplify-and-Forward)為概念為基礎之下，在合作式通訊網路中分散式偵測的問題。因為通道係數對於系統而言是未知的，所以結合式偵測與估測被考慮在本論文中。在論文中所提出來的方案不同於現存的分散式偵測與估測，它是利用節點之前的合作來達到更好的效能。然而對照現有的估測與偵測問題，本篇論文是基於假設在訊號端與中繼端之間的通道是相關性的。我們是使用最大期望值演算(EM Algorithm)法來解決我們所假設的問題。從模擬圖中我們可以明顯看出，所提出的架構會有一個不錯的效能改善。而且得到的結果顯示出疊代斂速度快速，這意味著此
架構可以在即時工作上應用。

In this thesis, we consider the problem of distributed detection problem in cooperative communication networks when the channel state information (CSI) is unknown. The amplify-and-forward relay strategy is considered in this thesis. Since the CSI is assumed
to be unknown to the system, the joint detection and estimation approach is considered in this work. The proposed scheme in this work differs from existing joint detection and estimation schemes in that it utilizes a distributed approach, which exploits node
cooperation and achieves a better system performance in cooperative communication networks.
Moreover, by contrast to the existing channel estimation and symbol detection schemes, the proposed scheme is mainly developed based on the assumption that the data communication from the source to each relay node is to undergo a correlated fading channel. We derive the joint detection and estimation rules for our problem using the expectation-maximum (EM) algorithm. Simulation results show that the proposed scheme can perform well. Moreover, the obtained results show that the proposed iteration algorithm converges very fast, which implies the proposed scheme can work well in
real-time applications.

1 Introduction 1
2 Review of EM Algorithm 5
3 System Model and Problem Formulation 9
4 Derivation of Relay and Destination Rules 13
4.1 Estimation at the Relay Nodes . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2 Joint Detection and Estimation at the Destination Nodes . . . . . . . . . . 15
5 Simulation results 19
6 Conclusion 26

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