本論文是使用現在家庭中的常見的Wi-Fi訊號做為都卜勒雷達系統的訊號源，並結合IQ正交解調的接收機架構，去進行人體生理監測及測距的實驗。由於Wi-Fi 訊號裡含有振幅調制成份和相位調制成份，使得雷達系統的感測性能不佳，為了改善雷達的性能，藉由本實驗室提出的注入鎖定技術以及雙通道雜訊抵消法去抑制此兩種調制成份，使得都卜勒訊號品質提升，進而能夠量測到人體的呼吸和心跳。
為了使Wi-Fi 雷達擁有如頻移鍵控(FSK)雷達的測距能力，本論文提出利用兩不同載波頻率之Wi-Fi訊號配合兩種校正內部電路延遲的方法，來獲取正確的相位差以得到正確距離資訊，接下來為了實現多人生理訊號監測，使用數位波束成型架構搭配兩種直流準位偏移校正方法，並利用雙通道解調方法抵銷雜訊，不僅可以清楚分辨不同人所在的方位還能感測到他們的呼吸及心跳。

The aim of this thesis is to develop a passive Wi-Fi Doppler radar based on a quadrature-demodulation receiver architecture. The system uses Wi-Fi as a transmit signal which is a ubiquitous signal at home and processes the echo signal of Wi-Fi to detect vital signs and perform ranging. Since the Wi-Fi signal contains AM and PM components, the sensing performance of the radar system is often poor. In order to improve the performance of the radar, the injection-locking technology developed in the laboratory was adopted. Moreover, the dual-channel noise cancellation method was used to suppress these two modulation components, so that the Doppler signal quality was improved, and the human respiration and heartbeat were measured.
In order to perform ranging, the radar uses two Wi-Fi signals with different carrier frequencies to behave as a frequency-shift keying (FSK) radar. Moreover, this study proposes two calibration methods to eliminate the internal circuit delay for obtaining the correct phase difference and distance information. Next, in order to detect the multipersons’ vital signs, in addition to using two DC offset removal methods, a digital beamforming architecture with dual-channel demodulation was established to measure the azimuth and vital-sign information for each person.

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 v
圖次 vii
表次 x
第一章 序論 1
1.1 研究背景與動機 1
1.2 被動式雷達簡介與應用 2
1.3 波束成型簡介 4
1.4 章節規劃 5
第二章 生理監測與定位之Wi-Fi感測技術 7
2.1 Wi-Fi調制抵銷技術 7
2.1.1 前言 7
2.1.2 雙通道雜訊抵消法與直流準位校正 7
2.1.2.1 Wi-Fi雜訊的分析與直流準位的校正 7
2.1.2.2 雙通道雜訊抵消法與實驗步驟 9
2.2 頻移鍵控(FSK)技術 11
2.2.1 距離追蹤理論 11
2.2.2 直流準位校正程序[17] 13
2.2.3 電路內部延遲 17
2.2.4 實驗系統設置 22
2.2.5 利用Wi-Fi訊號做訊號源之實驗結果 24
2.3 實驗討論 28
第三章 多人生理監測之Wi-Fi感測技術 30
3.1 前言 30
3.2 相位陣列簡介 30
3.3 陣列天線設計 33
3.4 訊號處理與校正程序 35
3.4.1 理論模型與模擬 35
3.5 Wi-Fi干擾實驗 37
3.6 波束成型多人生理監測 39
3.5.1 實驗系統設置 39
第四章 結論 46
參考文獻 47

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