A phase-extraction technique with multiple frequencies of a frequency-modulated continuous-wave (FMCW) radar is proposed, which allows the detection of target motions exactly. An FMCW chirp signal is decomposed into multiple-frequency continuous-wave (CW) signals to extract modulated phases due to target motions. The demodulated phases at multiple frequencies are summed and averaged. Since the proposed method can extract the phase without performing a fast Fourier transform (FFT), it can overcome the range migration problem, which causes an error in phase extraction using a conventional FFT-based method. Therefore, the proposed method can reduce spurious noises induced by phase errors compared with the conventional method. This was verified experimentally for both human vital sign detection and body motion tracking.

中文翻译：

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用于人体运动跟踪的多频调频连续波雷达相位提取方法

提出了一种调频连续波(FMCW)雷达的多频率相位提取技术，可以准确检测目标运动。FMCW 线性调频信号被分解为多频连续波 (CW) 信号，以提取由于目标运动而产生的调制相位。将多个频率的解调相位相加并求平均值。由于所提出的方法可以在不执行快速傅里叶变换（FFT）的情况下提取相位，因此可以克服距离迁移问题，这会导致使用传统的基于 FFT 的方法提取相位时出现误差。因此，与传统方法相比，所提出的方法可以减少由相位误差引起的杂散噪声。这在人体生命体征检测和身体运动跟踪方面都得到了实验验证。