使用選擇性映射以及部份傳送序列降低正交多工正交相位調變訊號之峰均功率比

Abstract

在本篇論文中，我們將探討一新型調變家族-正交多工正交調變(Orthogonally Multiplexed Orthogonal Phase Modulation，簡稱 OMOPM)訊號之峰均功率比（peak-to-average power ratio，簡稱PAPR）的效能趨勢。根據此一家族的定義內容，只需要適當的指定調變參數以及選擇適當的正交基底函數集合，便可以囊括了新的調變形式以及傳統的調變形式，正交分頻多工調變（OFDM）技術也是其中的一個特例。在多載波傳送技術裡，峰均功率比過大的問題將會造成訊號的非線性失真，此非線性失真現象會導致系統的效能品質受到嚴重的影響。 本論文主要研究方向就是在於討論如何找出適當的方法來讓PAPR的值有效變小。在此我們嘗試使用兩種線性的方法-選擇性映射（Selective Mapping，簡稱SLM）以及部分傳送序列（Partial Transmit Sequence，簡稱PTS），來做為減少PAPR的方法。最後我們會比較選擇性映射與部份傳送序列這二種方法所能降低的峰均功率比值以及系統所需的複雜度，來找出既能降低峰均功率比以及兼顧系統複雜度的方法。

In this thesis, we will discuss a new family of orthogonally multiplexed orthogonal phase modulations. We analyze the peak-to-average power ratio (PAPR) of the orthogonally multiplexed orthogonal phase (OMOPM) signals and observe its performance trends. According to the definition of the OMOPM family, we only need appropriate parameters and proper sets of orthogonal basis function. We can include new and traditional forms of modulation. Orthogonal frequency division multiplexing (OFDM) is one of the specific example. The problem of large PAPR will cause the nonlinear distortion of signals in multicarrier transmissive technique. The thesis concentrates on how to find a suitable method to diminish the value of PAPR efficiently. Thus, we will try two linear approaches- Selective mapping (SLM) and Partial transmit sequence (PTS), as a way to diminish PAPR. Finally, we will compare the PAPR that we can reduce using SLM and PTS and the complexity of system. Then, we find out the better way which can diminish PAPR and maintain the complexity of system at the same time.