Design Of Signal Processing System For Radar-Based Life Detector

The technology of radar-based non-contact life detector develops rapidly recently, and the theory is that using microwave beams to illuminate the human subject, then the reflected wave will be modulated by the surface movement resulting from the physical activity. By this way, some parameters of the reflected wave, such as frequency and phase will be changed.Using some special hardware circuits and software to detect these changes, then the life parameters such as respiration rate and heartbeat rate will be extracted from those changes.Signal processing system is an important part of the life detector. Study of this topic has completed the periphery of the signal circuit design as the core of powerful high-speed floating-point digital signal processor (DSP) TMS320C6713, this design can reduce the size and power consumption of the equipment effectively.Life characteristic signal is belong to slow moving target signals, its Doppler shift is very small, weak echo signal would be easily lost in the background of strong clutter. It is the focus of this study that detect and extract the weak target signal effectively and accurately. Paper presents a signal detection algorithm based on the traditional wavelet transform, selects the Symlets wavelet coefficients for signal extraction. The simulation results show that the wavelet transform algorithm can extract the life characteristic signal accurately.