張進福臺灣大學:電信工程學研究所陳建綸Chen, Chien-LunChien-LunChen2010-07-012018-07-052010-07-012018-07-052009U0001-2207200923222800http://ntur.lib.ntu.edu.tw//handle/246246/188343本研究主要在於討論在多輸入/多輸出正交分頻多工系統環境下，空間分集技術加入子載波功率配置之問題。在傳統的多輸入/多輸出空間分集下，不同的正交振幅調變符元被安置在不同的時槽上傳送，因此受到較高通道增益之符元無法分配功率至受到較低通道增益之符元上。本論文即在多輸入/多輸出正交分頻多工系統環境下，使用空間分集技術加入子載波功率配置之概念，令接收端解調時之位元或符元錯誤率進而降低。並針對加入子載波功率配置之系統，分析其計算複雜度、對通道估測誤差之容錯能力以及對於接收端回饋資訊的依賴程度。論文最後綜合比較以上分析之結果，並歸納出最適合於上、下行傳輸中使用之方法。This thesis is mainly discussing about the issue of spatial diversity for MIMO-OFDM systems with power allocation on subcarriers. The spatial diversity techniques in traditional MIMO systems transmit the QAM symbols in different time slots, and therefore the symbols which get the higher gain can not share its power to which get the lower gain. In this thesis, different spatial diversity techniques for MIMO-OFDM systems with power allocation on subcarriers were purposed to reduce the bit error rate. Computational complexities, robustness and dependence upon feedback information of different techniques mentioned above were analyzed. Finally, we compare the results and conclude the most suitable method in upload and download situations.口試委員會審定書................................................................................ ii謝........................................................................................... iii文摘要........................................................................................ iv文摘要......................................................................................... v一章 緒論...................................................................................... 1 1.1 研究背景................................................................................. 1 1.2 研究動機................................................................................. 2 1.3 無線通道環境介紹......................................................................... 3 1.3.1 前言............................................................................... 3 1.3.2 通道環境之參數..................................................................... 4 1.3.3 通道模型.......................................................................... 10 1.4 正交分頻多工系統簡介.................................................................... 14 1.5 論文架構................................................................................ 20二章 空間分集技術在多輸入/多輸出正交分頻多工系統下合功率分配之可行性............................................................................ 21 2.1 多輸入/多輸出天線系統................................................................... 21 2.2 空間分集................................................................................ 24 2.2.1 接收分集.......................................................................... 24 2.2.2 傳送分集.......................................................................... 25 2.2.3 傳送與接收分集.................................................................... 26 2.3 最大比例結合............................................................................ 28 2.4 時空/時頻區塊碼......................................................................... 31 2.5 最大比例傳輸............................................................................ 37 2.6 改良之最大比例傳輸...................................................................... 41 2.7 多載波系統下之功率分配.................................................................. 43 2.8 系統流程方塊圖.......................................................................... 47 2.9 模擬結果................................................................................ 50 2.9.1 空間分集加入功率分配：分集增益在子載波上的分佈情形.................... 51 2.9.2 空間分集加入功率分配：位元錯誤率..................................... 54 2.9.3 空間分集加入功率分配：分集增益之累積分佈函數......................... 55 2.9.4 空間分集加入功率分配：多路徑通道與分集增益之關係....................... 57 2.10 本章回顧與結論......................................................................... 60三章 應用功率分配技術時系統之計算複雜度與容錯能力.................... 63 3.1 計算複雜度分析.......................................................................... 63 3.1.1 計算複雜度公式.................................................................... 64 3.1.2 計算複雜度比較.................................................................... 65 3.2 多輸入/多輸出正交分頻多工系統之訓練符元與通道估測....................... 68 3.3 容錯能力分析............................................................................ 73 3.3.1 容錯能力的重要性.................................................................. 73 3.3.2 訓練符元訊雜比維持定值之情形...................................................... 74 3.3.3 訓練符元訊雜比維持與信號訊雜比相同之情形.................................... 78 3.4 本章回顧與結論.......................................................................... 85四章 結合功率分配之空間分集技術對於回饋資訊之依賴程度..................... 87 4.1 回饋資訊之量化問題...................................................................... 87 4.2 減少回饋資訊的方法...................................................................... 90 4.2.1 時域上減少回饋資訊................................................................ 90 4.2.2 頻域上減少回饋資訊................................................................ 91 4.3 模擬結果................................................................................ 94 4.4 本章回顧與結論.......................................................................... 99五章 總結.................................................................................... 101 5.1 各章回顧及結論......................................................................... 101 5.2 未來研究方向........................................................................... 104考文獻....................................................................................... 1051697575 bytesapplication/pdfen-US多輸入/多輸出正交分頻多工系統空間分集最大比例結合最大比例傳輸計算複雜度衰減通道最小均方誤差等化器MIMO-OFDMSpatial DiversityMRCMRTComputational ComplexityFading ChannelMMSE Equalizerthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188343/1/ntu-98-R96942100-1.pdf