多輸入多輸出中繼系統能有效改善訊號傳輸的可靠性及擴展通訊的涵蓋範圍。然而，在合作式通訊系統中，一般中繼端皆採用半雙工機制，分別利用接收與傳送兩階段，幫忙來源端傳送信號至目的端。由於半雙工中繼端需要兩階段傳送單一信號，頻譜使用效率低，因此研究者發展出全雙工多輸入多輸出中繼端系統，有效改善頻譜效率。然而，全雙工中繼端同時進行傳送跟接收信號，中繼端會因為接收到中繼端傳送的資料進而產生自我干擾，此干擾將會大幅地限制整體終端到終端之間的效能。為了降低自我干擾的影響，許多論文著重於中繼端預編碼的設計，抑制自我干擾的影響。然而，在頻率選擇性通道衰落通道環境時，預編碼設計較為困難。因此本論文將設計來源端及中繼端空時濾波器去減少頻率選擇性衰落通道及自我干擾所造成的影響，強化接收效能。由於中繼端自我干擾的影響，中繼端輸入和輸出信號的關係可以模式化為無限脈衝響應濾波器，我們考量來源端到中繼端鏈路及中繼端到目的端鏈路的通道，設計非線性連續干擾消除中繼端空時濾波器，抑制自我干擾的影響。在本論文中我們採用最小均方錯誤及最大化整體容量準則設計預編碼，我們先將時域信號轉成頻域信號簡化處理，然而所對應的最佳化問題形式複雜，不容易找到最佳解，因此，我們提出一連串的簡化處理方式，最終以疊代形式得到一種次佳解析解。由模擬結果得知，我們所提出的方法可以顯著優於其他現有的方法。

The multiple-input multiple-output relay (MIMO relay) systems are developed to efficiently improve the link reliability and extend the communication coverage. However, the relaying process needs two phases to separately receive and re-transmit signals, which is so-called half-duplex transmission. The full-duplex (FD) MIMO relay systems are then developed to improve the spectral efficiency. However, the relay nodes incur self-interference due to simultaneous receive and transmission of data signals, which greatly limits the overall end-to-end performance. Therefore, many works focus on the relay precoder design to mitigate the influence of the self-interference. However, in the presence of frequency selective fading channels, the design is much more involved. In this thesis, we jointly design source and relay space-time filters to mitigate the influence of both frequency selective fading channel and the self-interference caused by FD device. Since the relation of the input and output signals caused by the self-interference at the relay can be modeled as IIR filter, we develop a nonlinear successive interference cancellation (SIC) based relay space-time filter to suppress the self-interference and meanwhile leverage the channels of the source-relay and relay-destination links. The proposed joint source and relay space-time filters are conducted by minimum mean-squared error (MMSE) and maximum overall capacity. However, the corresponding optimizations are intractable to be solved due to the complicated formulations. We then propose a serious simplification process that can iteratively obtain the closed-form solutions. Numerical results show that the proposed design can significantly outperform the other existing methods.

論文審定書 i
致謝 ii
中文摘要 iii
英文摘要 iv
目錄 v
圖次 vii
第1章 序言 1
第2章 系統模型 8
第2.1節 多輸入多輸出全雙工中繼系統模型 8
第2.2節 最小均方錯誤接收機頻域系統模型 10
第3章 最小均方錯誤準則之最佳空時濾波器設計 14
第3.1節 最佳化問題描述 14
第3.2節 來源端與中繼端濾波器設計 15
第4章 最大化通道容量準則之最佳濾波器設計 20
第4.1節 最佳化問題描述 20
第4.2節 來源端與中繼端濾波器設計 21
第5章 系統模擬及探討 25
第6章 結論與未來展望 29
參考文獻 30
附錄A 32
附錄B 34
附錄C 36
附錄D 39

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