在這個的研究裡，我們所考慮的是一個半雙工(Half Duplex)、中繼端採放大後前送(Amplify-and-Forward, AF)的雙向中繼網路 (Two-Way Relay Network) 架構，其中裡面包含了各擁有一根天線的兩個來源端(Source Node)，以及各擁有兩根天線的兩個中繼端(Relay Node)。傳統的類正交空時區塊編碼(Quasi-Orthogonal Space-Time Block Code, QOSTBC)和類正交空頻區塊編碼(Quasi-Orthogonal Space-Frequency Block Code, QOSFBC)皆可以使用在這個架構中，但因為在某些非對角項元素上有非零值，所以沒辦法達到全散度(Full Diversity)的特性，此外，在目的端(Destination Node)必須使用複雜度較高的解碼器才能將訊號解出。在本篇研究中，我們提出一個可以同時達到全散度和全速度(Full Rate)的新分散式類正交空時區塊編碼(Distributed Quasi-Orthogonal Space-Time Block Code, D-QOSTBC)以及分散式類正交空頻區塊編碼(Distributed Quasi-Orthogonal Space-Frequency Block Code, D-QOSFBC)。我們提出在做完傳統的QOSTBC和QOSFBC後對中繼端上的兩根天線做相位旋轉，在第二個中繼端上，其中一根天線旋轉一個固定角度，另一根天線則是必須從已知的通道狀態資訊(Channel State Information, CSI)來求得旋轉角度。我們所提出的方法不僅可以同時達到全散度和全速度，而且在目的端可以使用低複雜度的解碼方式就將訊號解出。最後也會以模擬圖驗證我們所提出的D-QOSTBC和D-QOSFBC在位元錯誤率(Bit Error Rate, BER)上可以比傳統的QOSTBC和QOSFBC提升許多效能。

This thesis considers a half-duplex amplify-and-forward two-way relay network consisting of two single-antenna sources and two relays, each having two antennas. Both traditional quasi-orthogonal space-time block code (QOSTBC) and quasi-orthogonal space-frequency block code (QOSFBC) can be adopted in this system to obtain spatial, but not full, diversity gain. Additionally, the computational complexity of the receiver is extremely high. This thesis proposes a novel full-diversity and full-rate distributed QOSTBC/QOSFBC in a two-way two-antenna relay network. Following traditional QOSTBC/QOSFBC, a fixed phase rotation is performed on one of the two encoded signals at the second relay. Meanwhile, another encoded signal at the second relay is rotated by a given phase, which is generated from a known channel state information. Consequently, the proposed scheme offers two significant advantages. First, the proposed scheme can achieve both full diversity and full rate. Second, the computational complexity of the receiver is significantly reduced. Simulation results indicate that the bit-error-rate (BER) performance of the proposed distributed QOSTBC and QOSFBC is better than that of the traditional QOSTBC and QOSFBC because the former achieves full diversity.

第一章 導論+1
1.1 研究動機+2
1.2 論文架構+3
第二章 系統介紹 +4
2.1 雙向中繼網路架構+4
2.2 空時區塊編碼及空頻區塊編碼+7
2.2.1 正交空時和空頻區塊編碼+7
2.2.2 類正交空時區塊編碼+10
2.2.3 分散式空時和空頻區塊編碼+12
第三章 系統架構+14
3.1 傳統D-QOSTBC編碼方式+14
3.2 Gong提出的D-QOSTBC編碼方式+21
第四章 提出全散度全速度之編碼方式+27
4.1 全散度全速度之D-QOSTBC編碼方式+27
4.2 全散度全速度之D-QOSFBC編碼方式+43
4.3 中繼端轉兩根天線情況+51
第五章 模擬結果與討論+53
第六章 結論+61
參考文獻+62
中英對照表+69
縮寫對照表+73

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