本文提出混合頻率調變連續波與頻率偏移調變之雷達將發揮各自的雷達特性，以達成使用相同的頻寬下之更高的可解析距離，使得雷達的頻譜使用效率有所改進，所以於未來物聯網應於在醫院、家庭之照護等場合時，不再佔據大量頻寬，壓縮其他感測器的可使用頻寬，使得採用雷達作為長期生理訊號監測的可能性大幅提升。
於理論分析可得出，本系統提出之架構不再直接分離兩個目標的拍頻訊號，而是轉換至都卜勒頻率的維度進行訊號的距離分析，所以不再仰賴較大的頻寬以改善距離解析度，因此能夠達成更好的可解析距離。透過數值模擬軟體可以發現本方法於量測生理訊號，如:呼吸、心跳等微小訊號時，仍能透過其產生的都卜勒頻率對應之相位差來計算距離，並於初步模擬中討論此方法的侷限性，以及於理論得出之總頻寬的使用與可解析距離之間的比較。接著將在實驗中，驗證此方法的實際應用情況，首先將以兩個馬達乘載金屬片作為目標以替代人體的生理訊號，以利初期實驗的可重複性以及正確性，此方法的可行性被驗證過後，將利用馬達的可重複性，來驗證理論公式得出之總頻寬的使用與可解析距離之關係。其後進入多人實驗，可以發現人體實際的呼吸、心跳訊號都能夠對應出待測者的距離，接著就可以利用都卜勒頻率對應的距離來區分出訊號。最終從實驗數據，可以得出本系統改善了目標間之最小距離，從100 cm下降至約50 cm，改善之比例約為1.8倍，相較於過往文獻改善解析度的比例，有著明顯的成長，而量測到的心跳訊號之錯誤率小於3%，而量測距離的正確率則大於90%。

This thesis presents a novel waveform, which is hybrid frequency modulated continuous wave (FMCW) and frequency shift keying (FSK) radar to improve the distinguishable range in FMCW system. For traditional FMCW radar, the range resolution is inversely proportional to the bandwidth of radar, which becomes a bottleneck when the bandwidth is limited. However, the proposed approach generates additional overlapped chirp waveform, and therefore the FSK theory is used. Then, the targets in the same range bin can be distinguished in the Doppler frequency domain. The corresponded phase difference can be calculated, and so the distances of the targets. Hence, the targets are differentiated by the distance through the proposed method. Because the measured dimension is changed from the beat frequency to the Doppler frequency, the fundamental theoretical limit of range resolution is overcome and better spectrum efficiency is achieved. Therefore, the proposed waveform realizes better spectrum efficiency and lowers the complexity of the radar system.
In this thesis, the theory of the proposed method is derived, and the mathematic simulation is carried out to exhibit the feasibility under the premise that targets have different Doppler frequencies. Also, the effect of central frequency difference is demonstrated, so the distinguishable range can be improved if the central frequency difference is increased. For time-frequency analysis of the Doppler frequency, the wavelet transform is applied to achieve better the frequency resolution, and the choice of mother wavelet is displayed. The two-subject experiment is performed to verify the proposed method and the effect of the central frequency difference. From the experimental results, the minimum distance between targets is around 0.5 m under 150 MHz bandwidth, corresponded to 1 m range resolution. That is, the ration of improvement is 1.85, which is larger than previous works. Also, the accuracies of heartbeat frequency and distance are 97% and 90%, respectively.

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