Experimental study in breath detection and human target ranging in the presence of obstacles using ultra-wideband signals

The problem of detecting and localizing human breath activities in the presence of obstacles using an ultra-wideband radar is addressed in this paper. An extensive measurement campaign performed in realistic environments is presented. A breath activity generalized likelihood ratio detector as well as human distance and breath rate estimators are proposed based on the definition of a novel time-variant channel response model. The robustness of the detector and the ranging accuracy are investigated using experimental data showing that a hidden person can be detected and localized in many of the scenarios considered.