臺灣博碩士論文加值系統

空時編碼組(STBC)的通道特性使得接收端在還原訊號時不需要使用太複雜的等化器，而多輸入多輸出(MIMO)系統，可以在不增加頻寬的環境下增加傳輸的訊號量，目前已廣泛的使用在無線區域網(WLAN)，無線都會型網路(WMAN)，無線射頻辨識系統(RFID)….等，正交分頻多工(OFDM)利用不同頻率的子載波傳送訊號，而每個子載波具有窄頻寬的特性使通道頻率選擇性衰減的影響變小。本篇論文採用新提出的方法在CP-OFDM以及MIMO-STBC-OFDM的系統下皆能夠等效產生數倍的傳送訊號，使我們在只有少量的資料數的情況下做子空間通道估測時，能達到準確的效果。估測出來的通道應用在ZF等化器上，可以發現由於我們的通道準確效能提高，所以在資料筆數少的情況下也能快速的達到收斂。

The space–time-block-code (STBC) multiple-input- multiple-output (MIMO) cyclic-prefix orthogonal frequency-division multiplexing (CP-OFDM) provides a good performance for the multiuser scenario. In this thesis, the channel impulse responses of the space- time-coded MIMO CP-OFDM system are shown to be identifiable up to two ambiguity matrices by subspace channel estimation. The time domain zero-forcing equalizer (ZF)) is used to detect OFDM symbols. Based on the Circular structure of channel matrix, We propose a novel approach to largely increase the number of OFDM symbols. The proposed subspace channel estimation can converge within a small amount of OFDM symbols.

摘要 . i
英文摘要 . ii
誌謝 . iii
目錄 . iv
表目錄 . vi
圖目錄 . vii
第一章 緒論 1
1.1 正交分頻多工(OFDM)系統概述 2
1.2 循環字首(Cyclic Prefix, CP) 4
1.3 空時區塊碼概述(Space Time Block Coding, STBC) 5
1.4 盲目通道估測(Blind Channel Estimation) 6
1.5 論文大綱 7

第二章 MIMO-OFDM系統之盲目通道估測 8
2.1 單輸入單輸出(SISO)的CP-OFDM系統模型 9
2.2 多輸入多輸出(MIMO)的CP-OFDM系統模型 12
2.3 子空間通道估測(Blind Subspace Channel Estimation) 15
2.4 符元偵測(Symbol Detection) 17
2.4.1 ZF(zero forcing)等化器 17
2.5 循環排列矩陣(Circular Permutation matrix, CRM) 18
第三章 MIMO-STBC-OFDM系統之盲目通道估測 20
3.1 多輸入多輸出(MIMO)的STBC-OFDM 系統模型 20
3.2 子空間通道估測(Blind Subspace Channel Estimation) 24
3.3 符元偵測(Symbol Detection) 28
3.3.1 ZF(zero forcing)等化器 28
3.4 循環排列矩陣(Circular Permutation matrix, CRM) 28
3.5 總結 31
第四章 電腦模擬 33
第五章 結論與未來展望 43
參考文獻...... 45
附錄1 48

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