Research On High-accuracy Measurement Of Human Life Signal Based On Terahertz Radar

The superior Doppler characteristics of Terahertz(THz)radar make it very suitable for the measurement of micro-motion signals.Human life signals mainly include respiratory signals and heartbeat signals,which is a common typical micro-motion signal.Based on the terahertz frequency band,this paper explores the high-precision measurement algorithm of human life signal,which provides a new idea for the measurement of human life signal in the terahertz band.Firstly,the terahertz radar life signal echo model and measurement system are designed,and experiments are carried out based on the system,which provides experimental data support for subsequent algorithm analysis.Then the life signal extraction algorithm based on phase ranging is studied.The anti-noise performance and running time of the algorithm are studied.The feasibility analysis shows the shortcomings of the algorithm and the advantages of time.In addition,the problem of modal aliasing is easy for the Empirical Mode Decomposition(EMD)algorithm and the independent component analysis(ICA)algorithm requires the limitation of multi-channel input.An EMD-ICA joint is proposed.Extraction algorithm.Compared with the traditional phase ranging method,it can realize human life signal extraction at a lower signal to noise ratio.Finally,for the EMD-ICA algorithm,when the signal-to-noise is too low,the precision of life signal precision extraction is insufficient.A life signal denoising method based on Singular Spectrum Analysis(SSA)is proposed.By adjusting the signal-to-noise ratio,the Monte Carlo error curves of the three algorithms are drawn,and their advantages and disadvantages and their applicable scope are pointed out.The results show that the SSA-based noise reduction method can achieve high-precision extraction of human life signals in the terahertz band,which provides a new idea for the extraction of life signals in the terahertz band.