“…In the literature, solutions for the detection and distinguishing of people from other objects, e.g., behind a wall, using a UWB radar [16] and the two-dimensional fast Fourier transform (FFT) [17], are also proposed. In addition, the detection of direct visibility conditions with a UWB radio interface in node-to-node communication was presented in [18][19][20], and, in [21], the authors investigated several other types of obstacles, such as wood, steel and the human body.…”