Vital Signal Enhancement Algorithm Based on Multi-Channel Fusion for UWB Radar

Ultra-wideband (UWB) radars play a significant role in non-contact vital sign monitoring, especially in post-disaster search and rescue. However, practical applications are hindered by weak physiological signals and reduced detection reliability when human targets are oriented away from the radar. In this paper, a multi-channel fusion method for minimum distortion vital signal detection is proposed to solve the above problems. Using one transmitting and five receiving antennas, the method combines imaging algorithms to locate potential human targets. After preprocessing, the echo signals are separated into vital and noise components. Firstly, a spatial-temporal prediction approach is employed to determine a set of optimal prediction transforms between different channels by minimizing the residual noise while ensuring minimal signal distortion approaches zero. Additionally, the optimal noise filter is then generated using these transforms. The noise correlation matrix is estimated from the inanimate signal part. Target realism is validated using output results and the band energy ratio (BER) parameter. Simulation and experimental results show that when the detected target does not directly face the radar, the target frequency can still be accurately obtained. The proposed method effectively enhances the vital signs in the echo signal, providing more robust target detection capabilities.