應用於多重單載波分頻多重存取系統中的分部傳送序列演算法

A New Partial Transmit Sequence Algorithm for PAPR Reduction in Multiple SC-FDMA Systems in Multiple SC-FDMA Systems

江建宏(Chien-Hung Chiang)

指導教授 ： 曹恆偉

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02973

摘要

多重單載波分頻多重存取(multiple single carrier frequency division multiple access, Nx SC-FDMA)系統為LTE-A上傳架構的一種可行模式。它結合了多個SC-FDMA串流，因此能增加傳輸率以及頻譜使用彈性。但是相較於傳統的SC-
FDMA架構，Nx SC-FDMA訊號有較高的峰值功率比(peak-to-average power ratio, PAPR)。
文獻裡有許多降低PAPR的方法，其中分部傳送序列(partial transmit sequence, PTS)為一種不造成訊號失真且能有效減少PAPR的技術。然而，傳統的PTS演算法複雜度高且需要傳送多餘資訊以提供接收方解碼。
本論文的研究主題為用於Nx SC-FDMA系統的PTS演算法。其主要目標為降低複雜度，不需側訊息並且維持PAPR壓制能力與位元錯誤率。因此提出的演算法有三個特色。第一，實現了新的相位因子以及樣本萃取方法，藉此大量降低需要計算的樣本數。第二，基於該組因子提出了新的相位序列搜尋法，進一步減少搜尋次數。最後，在不增加位元錯誤率下，無需側訊息即可簡單地解碼。相較於前人提出的架構，此方法計算複雜度合理且具有足夠的PAPR壓制效能與系統位元錯誤率。

關鍵字

多重單載波分頻多重存取 ； 峰值功率比 ； 分部傳送序列 ； 計算複雜度 ； 側訊息

並列摘要

Multiple Single Carrier Frequency Division Multiplexing Access (Nx SC-FDMA) system is a promising candidate scheme for LTE-A uplink. It consists of several traditional SC-FDMA streams thus can increase throughput and facilitate efficient use of fragmented spectrum. However, Nx SC-FDMA has much higher peak-to-average power ratio (PAPR) than traditional SC-FDMA system.
Partial transmit sequence (PTS) technique is one of the attractive scheme to reduce PAPR. This distortionless technique can get sufficient PAPR reduction in Nx SC-FDMA systems. On the other hand, the conventional PTS scheme has high computational complexity and requires additional information for decoding.
In this thesis, the research topic is to design a new PTS algorithm for Nx SC-FDMA systems. The major goals of this algorithm are low complexity, no side information while keeping PAPR mitigating ability and BER performance with Optimum PTS. Hence, the proposed algorithm is guided to three features. First, it utilizes new phase factors and a suitable sample extraction method. Second, it has a suboptimum phase sequence searching algorithm to reduce the number of candidates search. Finally, it can be decoded easily without side information. Comparing to previous works from others, the performance degradation of proposed method is little and the computational complexity is reasonable.

並列關鍵字

Nx SC-FDMA ； PAPR ； PTS ； computational complexity ； side information

參考文獻

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