廣義空間調變(Generalized Spatial Modulation, GSM)是一種在多輸入多輸出(Multi-Input Multi-Output)系統下的調變方式，結合天線上傳輸的訊號調變(Symbol Modulation)與傳送天線啟動組合(Transmit Antenna Combinations)作為傳送資料的星座點，此調變方式與一般垂直貝爾實驗室分層空時結構(Vertical-Bell Laboratory Layered Space-Time, V-BLAST)的最高速傳輸不同，在一個時間點不使用全部的天線做傳輸資料，因此在傳送端不需要太多射頻(Radio Frequency)電路，而在接收端也不會接收到多通道干擾(Inter-Channel Interference)因此比一般V-BLAST在傳送端與接收端的成本低很多。
在本篇論文中我們使用樹狀搜尋的系統降低GSM解調的複雜度，並且在此無線傳輸系統上加入外部編碼降低系統錯誤率，而我們主要以兩部分分析偵測系統，第一部份我們不加入外部編碼並且直接在GSM偵測器中做硬式判斷(Hard Decision)求取每個位元的值，並且與其他次佳(Sub-Optimal) 並低複雜度的解調方法比較錯誤率的表現與複雜度，最終我們使用低密度同位檢查碼(Low-Density Parity-Check, LDPC)做為系統的外部編碼，因此在GSM偵測器做軟式判斷(Soft Decision)求取每個位元的對數近似比值(Logarithm Likelihood Ratios)，我們可以在最後模擬結果中發現我們的作法比其他偵測器複雜度更低，並且在使用設計過的LDPC code下錯誤率可以最為接近最佳解。

Generalized spatial modulation (GSM) is a modulation method for MIMO system, which combine two part of information in transmitted data. One are transmit antenna combinations, and the other are the data sending on the active antennas. This method of modulation is different from Vertical-Bell Laboratory Layered Space-Time (V-BLAST), that doesn’t use all of the transmit antennas at the one time slot. There is no need for a large number of radio frequency at transmission side, and reduce the inter-channel interference at the receiver side. So the GSM cost is much lower than the V-BlAST at both of the transmission and receiver.
In this paper, we use the tree search algorithm to reduce the complexity of the GSM demodulator, and add the outer code to increase the error performance. We mainly analyze the detection system in two parts. Firstly, we propose a hard decision GSM detector for a GSM scheme that doesn’t include outer code, and compared to the other low-complexity detectors with the error performance and complexity. Finally, we use an low-density parity-check (LDPC) code as the outer code of the system. In addition, we can find that our algorithm has less complexity than other detectors in the final simulation results, and the error rate can be closest to the optimal performance when using the designed LDPC code.

論文審定書 i
誌謝 ii
中文摘要 iii
Abstract iv
圖次 vii
第一章 導論 1
1.1 研究動機 2
1.2 論文架構 3
第二章 系統模型 4
2.1空間調變多輸入多輸出之基本架構 4
2.2低密度同位檢查碼之基本架構 6
第三章 廣義空間調變多輸入多輸出的硬式偵測器 13
3.1排序最小均方差估計區塊 13
3.2碼字輔助硬式偵測器 16
第四章 廣義空間調變多輸入多輸出的軟式偵測器 21
4.1最大事後機率偵測器 22
4.2最小均方差估計軟式偵測器 23
4.3碼字輔助軟式偵測器 25
第五章 設計低密度同位檢查碼 28
第六章 模擬結果與討論 31
6.1硬式偵測錯誤率與複雜度比較 31
6.2軟式偵測器錯誤率比較 37

第七章 結論 44
參考文獻 45
中英對照表 48
縮寫對照表 52

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