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dc.contributor.author楊文廣zh_TW
dc.contributor.author桑梓賢zh_TW
dc.contributor.authorYang, Wen-Kuangen_US
dc.contributor.authorSang, Tzu-Hsienen_US
dc.date.accessioned2018-01-24T07:42:51Z-
dc.date.available2018-01-24T07:42:51Z-
dc.date.issued2018en_US
dc.identifier.urihttp://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070450271en_US
dc.identifier.urihttp://hdl.handle.net/11536/142987-
dc.description.abstract在實體層技術上,過去二十年當中,多輸入出傳輸(MIMO)可以增加頻譜效率而被廣泛的研究討論且商用化。從點對點傳輸(P2P)到多用戶輸入輸出傳輸(MU-MIMO),再到大規模多重輸入多重輸出(Massive MIMO),用戶可以共享頻譜資源,且通道硬化(channel-hardening)現象使得基地台下傳的預編碼器容易製作。 但是在大規模多輸入多輸出系統上傳時,基地台的大量天線同時收到訊號,傳統上,基地台欲使用此通道之前,常使用特徵值分解或奇異值分解方法來估計通道,然而實際上尤其在大規模多輸入多輸出系統時,特徵值分解方法需要得到大量樣本來做估計,實現將非常複雜。且在實際時變通道上,在估計完通道後,實際的通道也已經改變,萬一在更快的都普勒(Doppler)速度時,將無法正確追蹤通道。 這篇論文為了減少複雜度、有效追蹤通道以及使用最少的一個領航符元(pilot symbol),使用近似投影子空間追蹤(Projection Approximation Subspace Tracking with deflation)演算法,每個時間點更新上一個時間點的子空間來降低複雜度問題,使用一個領航符元,改善特徵向量角度模糊問題。最後以數值結果驗證在不同的時變通道下,系統的通道估計與追蹤表現。zh_TW
dc.description.abstractConventional semi-blind channel estimation schemes for massive MU-MIMO systems are based on eigenvalue decomposition (EVD) or singular value decomposition (SVD). However, EVD-based or SVD-based channel estimation would impose a high computational complexity when the base station is equipped with large number antennas. Those methods are not well-suited for practical real-time processing. In order to reduce the computational complexity, a PASTd-based channel estimation and tracking algorithm is proposed. The PASTd-based algorithm can converge fast, and has low computational complexity. Simulation results show the proposed PASTd-based semi-blind channel estimation can effectively track the channel with Doppler effect. Only one pilot symbol per user at the beginning of transmission is needed to resolve the ambiguity.en_US
dc.language.isoen_USen_US
dc.subject大規模多輸入多輸出zh_TW
dc.subject通道估計zh_TW
dc.subject通道追蹤zh_TW
dc.subject子空間追蹤zh_TW
dc.subject投影近似子空間追蹤zh_TW
dc.subjectMassive MIMOen_US
dc.subjectChannel Estimationen_US
dc.subjectChannel Trackingen_US
dc.subjectSubspace Trackingen_US
dc.subjectPASTen_US
dc.title以PASTd為基礎的大規模多輸入多輸出系統之通道追蹤zh_TW
dc.titlePASTd-based CSI Tracking in Massive MIMO Systemsen_US
dc.typeThesisen_US
dc.contributor.department電子研究所zh_TW
顯示於類別:畢業論文