基于小波变换的雷达生命信号提取方法  

Study on the Extraction Method of Radar Life Signal Based on Wavelet Transform

作　　者：杨秀芳[1] 张伟[1] 王若嘉[2] 杨宇祥[1] 杨大伟[1] 

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048 [2]伦敦大学学院土木与环境工程部

出　　处：《光子学报》2013年第11期1370-1374,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61273271);陕西省教育厅自然科学专项(No.12JK0527)资助

摘　　要：雷达非接触式检测生命信号因受环境噪音和被测对象微动等因素影响严重,而且这些干扰引起的多普勒信号的非平稳性,使其有用生命信号———呼吸信号和心跳信号用一般的信号处理方法(如数字滤波、快速傅里叶变换)无法提取出来.针对此问题,建立了连续波雷达生命信号模型,用K波段,频率24GHz,功率30mW的连续波雷达体制对一名30岁左右的健康男性进行了测量.测量在办公室安静环境下进行,雷达发射头距离被测对象2m,数据采集卡采样频率100Hz,对测量数据用dB3小波基函数进行了8尺度小波分解和重构,成功地在第七层低频重构和第六层的高频重构中提取到了人的呼吸信号和心跳信号.通过对这两层信号进行快速傅里叶变换,获得呼吸信号和心跳信号能量峰值处的频率值分别是0.29Hz和1.07Hz,用传统测量方法得到的频率值分别相差0.04Hz和0.03Hz,表明用小波变换提取和分离雷达生命信号中的呼吸信号和心跳信号方法是可行的,为将雷达非接触测量方法应用于临床监护和灾难营救等方面提供了理论依据和实验数据.Radar non-contact 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 signals-breathing 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 non-contact measuring life information has been established. Using K-band, frequency 24 GHz ,power 30 mW continuous wave radar system has measured a 30 years-old 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 low-frequency layer and sixth high-frequency 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 non-contact measurement method applied to the clinical monitoring and disaster rescue and so on.

关 键 词：小波变换 雷达生命信号模型 非接触测量 快速傅里叶变换 

分 类 号：TN314[电子电信—物理电子学]