在本論文中將空頻區塊碼(Space Frequency Block Code )與多輸入多輸出之正交分頻多工(Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing, MIMO-OFDM)兩種技術結合作為系統架構。對多輸入多輸出系統的接收端而言，通道估測對系統效能有關鍵的影響。在本論文中，我們採用半盲目的方式來進行通道的追蹤。當系統在追蹤通道時為依據當時通道的特性來選擇使用決策迴授機制或是改良式固定模數演算法(Modified Constant Modulus Algorithm)來進行估測。由分析結果得知，如此切換的方式加上空頻區塊碼本生的特性。比傳統僅使用決策迴授法或改良式固定模數演算法的效能更佳。

In the thesis, SFBC (Space Frequency Block Code) and MIMO-OFDM ( Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing ) are combined to construct the whole system. Channel estimation has the key effect to the system performance as far as the receiver of MIMO-OFDM is concerned. We also use a semi-bland method to trace the channel. When the system is tracing the channel, decision feedback or Modified Constant Modulus Algorithm(MCMA) can be chosen according to the property of the channel. From simulation, results, the switching method and the properties of the new SFBC method produces better bit error rate performance than traditional decision feedback or MCMA.

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