選擇性映射(Selected Mapping, SLM)架構通常被使用來降低正交分頻多工(Orthogonal Frequency Division Multiplexing, OFDM)系統中的峰均值功率比(Peak-to-Average Power Ratio, PAPR)。在[21]中已經證明了傳統SLM架構的計算複雜度可以被大大的降低，其藉由轉換向量(Conversion Vector)來取代傳統反快速傅立葉轉換(Inverse Fast Fourier Transform, IFFT)運算，而轉換向量可以利用相位旋轉向量(Phase Rotation Vector)的反快速傅立葉轉換來得到。然而很不幸的，在[21]中的轉換向量其所對應的相位旋轉向量的每個元素通常沒有相等大小(Magnitude)，因此位元錯誤率(Bit Error Rate, BER)的效能會遭受到顯著的變差。這個問題可以利用有完美序列(Perfect Sequence)形式的轉換向量來補救。之後我們提出了三種新的完美序列，而每種完美序列是由某一些基底向量與他們的循環位移(Cyclic-Shift)形式所組成。基於這些完美序列的獨特結構，我們提出了三個新的低複雜度SLM架構。由模擬結果得知，我們提出的架構其PAPR的效能跟傳統SLM架構相比雖然有些微的變差，但是這三個架構可以達到與傳統SLM架構相同BER的效能，而且其計算複雜跟傳統SLM架構相比均大大的降低。

Selected mapping (SLM) schemes are commonly employed to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. It has been shown that the computational complexity of the traditional SLM scheme can be substantially reduced by adopting conversion vectors obtained by using the inverse fast Fourier transform (IFFT) of the phase rotation vector in place of the conventional IFFT operations [21]. Unfortunately, however, the elements of these phase rotation vectors of the conversion vectors in [21] do not generally have an equal magnitude, and thus a significant degradation in the bit error rate (BER) performance is incurred. This problem can be remedied by utilizing conversion vectors having the form of a perfect sequence. This paper presents three novel classes of perfect sequence, each of which comprises certain base vectors and their cyclic-shifted versions. Three novel low-complexity SLM schemes are then proposed based upon the unique structures of these perfect sequences. It is shown that while the PAPR performances of the proposed schemes are marginally poorer than that of the traditional SLM scheme, the three schemes achieve an identical BER performance and have a substantially lower computational complexity.

第一章 導論............................................................................1
1.0 引言..................................................................................1
1.1 研究動機..........................................................................2
1.2 論文架構..........................................................................2
第二章 正交分頻多工系統與峰均值功率比........................3
2.0 引言..................................................................................3
2.1 正交分頻多工系統的架構.............................................3
2.2 反離散傅立葉轉換的應用..............................................6
2.3 循環字首的應用..............................................................7
2.4 OFDM訊號的峰均值功率比...........................................8
第三章 常見的降低PAPR方法...........................................13
3.0 引言................................................................................13
3.1 常見的降低PAPR方法簡介與比較.............................13
3.2 傳統SLM架構................................................................15
3.3 Wang和Ouyang提出的低複雜度SLM架構...............16
第四章 三個基於完美序列的低複雜度SLM架構.............21
4.0 引言................................................................................21
4.1 採用的完美序列/轉換向量的結構...............................21
4.1.1 種類一的完美序列/轉換向量...................................22
4.1.2 種類二的完美序列/轉換向量...................................23
4.1.3 種類三的完美序列/轉換向量...................................24
4.2 提出的低複雜度SLM架構............................................26
4.2.1 提出的架構一(Proposed Scheme I, PS I)...........26
4.2.2 提出的架構二(Proposed Scheme II, PS II)..........28
4.2.3 提出的架構三(Proposed Scheme III, PS III)........28
4.3 提出的架構的複雜度分析............................................31
第五章 PAPR與BER的效能模擬分析..............................35
第六章 結論.........................................................................39
中英對照表..........................................................................40
全名縮寫對照表..................................................................43
參考文獻..............................................................................44

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