臺灣博碩士論文加值系統

第四代行動通訊系統以正交分頻多工(Orthogonal Frequency Division Multiplexing, OFDM)為核心技術，可有效對抗通道選擇性衰落及提高頻譜效益，但容易受到頻率偏移導致錯誤率上升。為了達國際電信聯盟(International Telecommunication Union, ITU)所定訂的1Gbps的傳輸速率至少需要100MHz的頻寬，3GPP提出載波聚合(Carrier Aggregation, CA)的技術以有效分配及利用頻寬資源。本文第三章討論基於載波聚合的場景下，提出利用快速傅立葉轉換達低複雜度之盲蔽式頻率偏移估計法，相較文獻[1]方法可節省70%的計算複雜度且有效估計範圍更大。
MIMO系統中天線總數越多可使系統的傳輸量及頻譜效益提高，相對需要更大的計算複雜度，特別是對於所謂巨量天線(Massive MIMO)。本文第四章提出利用空間濾波與天線分組概念，減少不必要的天線計算以有效降低整體計算量，相較傳統天線可省去50%的計算複雜度，且有更好的效能表現。

Orthogonal Frequency Division Multiplexing (OFDM) was adopted for the fourth generation mobile communication system. OFDM system can mitigate the frequency selective fading and improve the spectral efficiency. However, it’s very sensitive to the frequency offset. To achieve the standard of International Telecommunication Union (ITU), the 100MHz bandwidth is necessary to have 1Gbps throughput. 3GPP proposes the Carrier Aggregation (CA) technique to utilize the spectral resource more efficiently. In Chapter 3, this thesis proposed a blind and low complexity algorithm for carrier frequency offset estimation based on Fast Fourier Transform. It can reduce the 70 percent computation complexity compared with the reference [1] and improve the estimation range in Carrier Aggregation scenario.
As the number of antenna increases, the throughput, spectral efficiency and computation complexity will be increased in the MIMO system, especially for the Massive MIMO. In Chapter 4, this thesis adopts the spatial filtering concept to reduce unnecessary antenna computations. It can reduce the 50 percent computation complexity and have a better performance compared with the conventional method.

摘要 I
Abstract II
目錄 III
圖目錄 IV
表目錄 VI
第一章 導論 1
1.1 背景簡介及研究動機 1
1.2 論文大綱 2
第二章 LTE-A系統簡介 3
2.1 正交分頻多工 3
2.1.1 簡介 3
2.1.2 主要同步訊號之自相關估測法[9] 6
2.1.3 最大概似之同步估測法[5] 8
2.2 載波聚合 11
2.2.1 簡介 11
2.2.2 基於MUSIC之多載波頻率偏移估計法[6] 13
2.3 多輸入多輸出系統 16
第三章 載波聚合之頻率同步 19
3.1 文獻方法[1] 19
3.2 利用快速傅立葉轉換之頻率偏移估計法 23
3.3 載波偏移與抵達來向的多重估計 31
3.4 實測通道分析 35
第四章 低複雜度之空間濾波MIMO接收器 38
4.1 文獻方法[2] 38
4.2 提出之低複雜度空間濾波MIMO接收器 42
4.3 模擬分析 47
4.4 實測通道分析 54
第五章 結論 56
參考文獻 57

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