臺灣博碩士論文加值系統

本篇論文主要內容為簡化PTS OFDM架構下的計算複雜度。在PTS架構下的多組IFFT中有許多零的加法與乘法運算。在IFFT架構中化簡這些運算可以在不影響運算結果與PAPR的降低效果的情況下簡化PTS OFDM架構的計算複雜度。運用此原理，本篇論文的第三章與第四章由改變IFFT的運算架構提出兩個新的PTS架構。在第三章中，我們刪除IFFT架構中零的加法與成法運算後可將此IFFT化簡成一個較小的IFFT與另外兩個簡單的乘法運算。如此一來，我們可有效降低此PTS OFDM架構的複雜度。在第四章中，如同第三章的原理，我們將所有IFFT中零的加法與成法運算化簡，再將所有分支得到的運算架構合併為一個IFFT架構。如此一來，多個分支的IFFT即可以一個IFFT架構取代，且其複雜度將簡化為原本的1/M。

In this paper, the complexity reduction of partial transmit sequence (PTS) scheme which is used for PAPR reduction in OFDM system by reducing the complexity in the IFFT architecture is investigated. In the IFFT architecture of PTS OFDM scheme, much calculation is the addition and the multiplication of zero, which is obviously unnecessary. Eliminating the calculation from the architecture can efficiently reduce the computational complexity without any effect to the resulting signal or the performance of PAPR reduction. In this word, two new PTS OFDM scheme are proposed in chapter 3 and chapter 4. In chapter 3, after eliminating the addition and multiplication of zeros, the IFFT can be reduce to a smaller size of IFFT and two other transform. Thus, the computational complexity can be efficiently reduced. In chapter 4, with the similar concept, after eliminating the unnecessary calculation, we can combine all the IFFTs of branches into just an IFFT architecture by using decimate-in-frequency (DIF) IFFT architecture. Thus, the computational complexity can be reduce to 1/M times of the complexity, which M is the number of the branches.

Chapter 1 Introduction...………………………………………………………………2
Chapter 2 Overview of the PTS OFDM System ……………………………………...4
2.1 OFDM System and PTS ………………………………………………..4
2.2 A PTS OFDM Scheme with Low Complexity-Decomposition PTS Sub-block Partitioning Scheme ………………………………………...6
2.3 A PTS OFDM Scheme with Low Complexity-Fractional PTS
Technique……………………………………………………………….8
Chapter 3 A New PTS OFDM Scheme with Low Complexity IFFT Implement Architecture ……………………………………………………………….10
3.1 The Conventional PTS Scheme ……………………………………….10
3.2 The Complexity Reduction of Interleaving Partition PTS Scheme……11
3.3 The Complexity Reduction of Adjacent Partition PTS Scheme ………17
3.4 The Computational Complexity ………………………………………20
Chapter 4 Another New PTS OFDM Scheme with Low Complexity IFFT Implement Architecture ……………………………………………………………….25
4.1 The Key Point of This Idea …………………………………………...25
4.2 Reducing the Complexity of the Algorithm …………………………..26
4.3 Improvement And Future Work………………………………………..36
4.4 The Computational Complexity ………………………………………37
Chapter 5 Conclusion ………………………………………………………………..40
Reference …………………………………………………………………………….41

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