Accurate Vital Sign Extraction by Variational Nonlinear Chirp Mode Decomposition

This study utilizes the Texas Instruments AWR1642BOOST 77 GHz millimeter-wave radar module to collect raw radar data. An All-Phase FFT is performed in the fast-time dimension to execute range FFT and obtain the complete phase signal. The arctangent algorithm is applied to identify the range bin corresponding to the human target and extract phase information. The phase signal is then demodulated and differentiated. The demodulated phase signal is separated using the Variational Nonlinear Chirp Mode Decomposition (VNCMD) algorithm. Compared to traditional methods (band-pass filtering, EMD, VMD) for processing respiration and heartbeat signals, the proposed algorithm demonstrates superior accuracy, validated against reference signals from the Texas Instruments ECG sensor ADS1292R.