Acta Photonica Sinica, Volume. 42, Issue 11, 1370(2013)
Study on the Extraction Method of Radar Life Signal Based on Wavelet Transform
Radar noncontact detection of life signals is severely affected by factors such as environmental noise and the micro movement of detecting object, and the Doppler signal nonstationarity that caused by the interference makes the useful life signalsbreathing and heartbeat signals cannot be extracted with general signal processing method(such as digital filtering, fast Fourier transform). According to this problem, the mathematical model of radar noncontact measuring life information has been established. Using Kband, frequency 24 GHz ,power 30 mW continuous wave radar system has measured a 30 yearsold healthy men. Measurement is carried out in a quiet office environment. There is 2 m distance between radar transmitting head and measure target. Data acquisition card′s sampling frequency is 100 Hz. The data measured are carried out eight scale wavelet decomposition and reconstruction by db3 wavelet basis function. It is success that extracted the person′s breathing and heartbeat signals on the seventh lowfrequency layer and sixth highfrequency layer respectively. Through fast Fourier transform processing of these two layers′ signals, the energy frequency value of the peak area is 0.29 Hz and 1.07 Hz. The frequency difference between the traditional measuring method and the wavelet transform method is 0.04 Hz and 0.03 Hz. The results show that the wavelet transform is used to extract and separate breathing and heartbeat in radar life signals is feasible. It will provide theoretical basis and experimental data for radar noncontact measurement method applied to the clinical monitoring and disaster rescue and so on.
Get Citation
Copy Citation Text
YANG Xiufang, ZHANG Wei, WANG Ruojia, YANG Yuxiang, YANG dawei. Study on the Extraction Method of Radar Life Signal Based on Wavelet Transform[J]. Acta Photonica Sinica, 2013, 42(11): 1370
Received: Apr. 26, 2013
Accepted: --
Published Online: Dec. 16, 2013
The Author Email: Xiufang YANG (yxf5078@163.com)