隨著科技快速發展，現代人對網路及多媒體倚賴越來越高，所需頻寬也越來越大，現有6 GHz以下可用頻寬已非常有限，在高頻段仍有大頻寬，能夠應付頻寬的需求，因此毫米波通訊成為下一代通訊中的熱門的候選。但在毫米波傳輸過程中，因傳輸訊號波長很短，能量衰減快，所以毫米波普遍採用大規模天線及波束成形使能量提升以達到傳輸效率。
波束成形技術中以波束追蹤技術作為輔助，讓基地台可以搜尋到使用者入射角與發射角，並且朝著這些角度傳輸資料，使傳輸效率提升。本論文主要著重於壓縮感知搜尋法的波束追蹤技術實現，在搜尋時間上快於傳統的窮舉法，但壓縮感知搜尋法會因收發兩端振盪器不一致，引起載波頻率偏移，導致波束追蹤錯誤，在實際應用中很難被實現，本論文提出有效的方法來估計載波頻率偏移，解決了這項限制。由於毫米波系統開發，高頻元件取得不易，所以本論文以長期演進技術系統於3.5 GHz頻帶作為基礎，進行波束成形與波束追蹤技術開發，並且利用羅德史瓦茲儀器結合軟體驗證平台，將壓縮感知搜尋法實際進行空口驗証。

With the rapid development of technology, more and more people rely on the network and multimedia. With the growing of the bandwidth demanding, the available carrier frequency below 6 GHz is limited. Because there still have large bandwidth in the high frequency band, millimeter-wave communication has become a popular candidate for the next generation mobile communication. However, in millimeter-wave transmission, the transmission signal wavelength is short, and the energy attenuates fast. Therefore, the large-scale antenna and beamforming are commonly used to the millimeter wave to improve the energy and achieve the efficiency of the transmission.
In beamforming, the beam tracking technology is commonly used in which the base station search for the angle of arrival and transmit the data toward the angle. The beam tracking can improve the efficiency of transmission. The paper mainly focuses on the realization of the beam tracking technique by using the compressed sensing (CS) searching method. The CS searching method is faster than the traditional exhaustive method. However, the CS searching method is sensitive to the carrier frequency offset (CFO) which results from the inconsistency of the oscillators at both ends. Because CFO always exits in practical communication systems, the CS searching method is difficult to be use in practical applications. In this thesis, we present an effective way to estimate the CFO that incorporates with the CS searching method. To verify our design, we use Long Term Evolution (LTE) technology system as the basis for the development of beamforming and the CS beamforming technology in the 3.5 GHz band.

目錄
第一章 緒論 1
1.1 研究背景與動機 1
1.2 論文架構 2
第二章 OFDM系統與LTE系統和波束成形介紹 3
2.1 簡介 3
2.2 OFDM系統架構 3
2.2.1單載波與多載波介紹 3
2.2.2正交分頻多工介紹 4
2.2.3串列與並列 6
2.2.4循環字首 7
2.3 LTE系統之概述 8
2.3.1 LTE主要技術項目 8
2.3.2 LTE訊框 (Frame) 架構 8
2.4 波束成形簡介 12
2.4.1 大規模天線系統 (Massive MIMO) 12
2.4.2 波束成形 (Beamforming) [8] 13
2.4.3 波束成形原理 15
2.5 羅德史瓦茲儀器介紹 17
第三章 波束追蹤介紹 18
3.1波束追蹤 (Beam Tracking) 18
3.2 波束追蹤方法 18
3.2.1 窮舉法 18
3.2.2 壓縮感知搜尋方法 19
3.3 窮舉法與CS搜尋法之比較 22
3.3.1 搜尋流程比較 22
3.3.2 複雜度比較 23
3.3.3 效能比較 24
第四章 波束追蹤實現 26
4.1 訊框設計 27
4.1.1 窮舉法起初訊框設計 27
4.1.2 窮舉法訊框改良 29
4.1.3 CS搜尋訊框設計 30
4.1.4 訊框整合 31
4.1.5 波束方向設計 32
4.2 波束追蹤實現 33
4.2.1 窮舉法系統 33
4.2.3 壓縮感知搜尋系統 34
4.2.4 載波頻率偏移問題 35
4.2.5 通道編碼簿波束訓練 36
4.2.5.1 通道編碼簿 36
4.2.5.2 利用通道編碼簿波束訓練 37
4.2.6 估測CFO 37
4.2.7 補償 CFO 39
第五章、模擬與實測結果 40
5.1 模擬結果 40
5.1.1 波束成形 40
5.1.2 窮舉法與CS搜尋法比較 42
5.2 實際測量結果 46
5.2.1 窮舉法線對接測量結果 46
5.2.2 窮舉法 Over The Air 實際測量結果 49
5.2.3 窮舉法與 CS 搜尋法 Over The Air 實際測量結果 55
第六章　結論 61
參考文獻 62

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