全雙工 (Full-duplex, FD) 正交多頻分工(Orthogonal frequency division multiplexing, OFDM)系統在傳送端與接收端同時地傳送資料，因此可以提供更好的頻譜效率。然而，實際上相位雜訊(phase noise, PHN)以及載波頻率飄移(carrier frequency offset, CFO)造成載波間相互干擾以及傳送訊號旋轉的現象。而這樣的現象會降低通道估測時的精準度，也就是會降低整個估測的效能表現，尤其當系統處於時變通道的環境中時，此現象會更加明顯。有別於傳統的半雙工系統，在全雙工系統中接收訊號會接收到自我干擾的影響，而自我干擾在時變的環境中同時也會受相位雜訊以及載波頻率飄移所影響。而時變通道在本質上可以利用複指數型的基底擴充模型(complex exponential basis expansion model, CE-BEM)來捕捉，此模型將時變通道用BEM係數來加以描述。本文提出了一個比現今的方法更實際的估測方式，即以EM為基底的演算法來同時估測在FD-OFDM系統中由BEM系數代表的通道、PHN以及CFO。

Full-duplex (FD) orthogonal frequency division multiplexing (OFDM) systems substantially provide higher spectral efficiency due to simultaneous communication of the uplink and downlink. However, phase noise (PHN) and carrier frequency offset (CFO) practically cause inter-carrier interference and rotation of transmit data signal, which degrades the accuracy of channel estimation as well as the performance of detection, especially in the time-varying channel environment. Unlike to conventional half duplex system, the received signals encounter the self-interference (SI) which is challengeable to be accuracy estimated in the presence of PHN and time-varying environment. The time-varying channel can essentially be captured by the complex exponential basis expansion model (CE-BEM), where the channel is described by the BEM coefficients. In this thesis, we propose an EM-based algorithm for joint estimation of BEM coefficients corresponding to self-interference and desired channels, PHN, and CFO in FD-OFDM systems, which is more general than the existing methods. Simulation results validate our joint estimation and show superiority over the existing methods.

論文審定書……………………………………………………………..………………..i
誌謝……………………………………………………………….……………...……...ii
中文摘要……………………….……………………………………..………………....iii
英文摘要………………………………………………………..…………...……….....iv
目錄……………………………………………………………..…………...……….....v
圖次……………………………………………………………….……………...……..vi
第1章 序言…………………………………………………………..........................1
第2章 全雙工正交分頻多工系統…………………………………..........................8
第2.1節 無線全雙工通訊系統模型………………………...………..…….............8
第2.2節 複數基頻正交多頻分工系統……………………………..……...............10
第2.3節矩陣形式訊號模型……………………………..…….............................11
第2.4節 BEM通道訊號模型……………………………..……...........................12
第3章 結合頻率飄移與通道估測演算法……………………………......................13
第3.1節 步驟E…………………………………………………..........................15
第3.2節 步驟M……………..…………………………………...........................18
第3.3節 初始值以及收斂設定………………………………............................19
第4章 系統模擬及探討……………………………………………………………......21
第5章 結論與未來展望……………………………………………………………......27
參考文獻…………………………………………………………………………….....28

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