臺灣博碩士論文加值系統

OFDM與MIMO的結合，是獲得高傳輸容量的有效方法。釵h新的無線傳輸標準，如802.11n, 802.16和802.20等都將這兩種種技術的組合定為基本的要求。OFDM藉由較長的符碼週期，可以有效的對抗多路徑通道產生的頻域選擇性衰減。配合MIMO系統使用的STBC則是可以獲得傳送端的分集增益，而大幅提高通道容量。多輸入多輸出正交分頻多工無線通訊系統中，雖然利用多根天線能夠提升系統效能，但多路徑通道的估計也變得更為複雜，通道估計的準確與否也更加直接影響了在接收端解回資料的準確性。在本論文中，利用數種通道估計法在多輸入多輸出正交分頻多工系統中估計通道，並比較不同方法間的優劣。

Orthogonal frequency division multiplexing (OFDM) in combination with the multiple-input-multiple-output (MIMO) antennas has been proven as an efficient way to achieve high transmission capacity. Many wireless communication systems have chosen the MIMO-OFDM as transmission scheme, such as 802.11n, 802.16 and 802.20, etc. OFDM provides robust transmission in multi-path fading channel. Space-time block code (STBC) is a popular way to construct MIMO systems. In MIMO-OFDM wireless communication systems, however, the multi-path channel estimations become more complicated. In this thesis, channel estimation methods are compared in a MIMO OFDM system

第一章 緒論 1
1.1 前言 1
1.2 研究動機 1
1.3 論文架構 2
第二章 多輸入多輸出正交分頻多工系統 3
2.1 多輸入多輸出簡介 3
2.2 正交分頻多工簡介 7
2.3 通道模型 16
2.3.1 無線通道之衰減 16
2.3.2 多路徑衰減通道之模型 19
2.3.3 空間通道模型 22
第三章 最小均方誤差通道估計 41
3.1 系統模型 41
3.2 最小均方誤差通道估計 43
3.2.1 基本通道估計法(basic channel estimation) 43
3.2.2 最佳訓練符元法(optimum training symbol) 46
3.2.3 簡化型通道估計(simplified channel estimation) 50
3.3 模擬結果 52
第四章 EM和SAGE通道估計 57
4.1 EXPECTATION MAXIMIZATION(EM)通道估計 57
4.2 SPACE-ALTERNATING GENERALIZED EXPECTATION-MAXIMIZATION (SAGE) 通道估計 63
4.3 模擬結果 65
第五章 結論 67

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