A Spatial Model of the UWB Off-Body Channel in Indoor Environments

In this paper, we present novel ultrawideband (UWB) off-body channel measurement campaigns in indoor environments aiming the characterization of the delay and the angular properties of the channel. Measurements were performed by using isolated UWB antenna and body-mounted antennas on different positions. Multipath and cluster parameters are estimated by means of space alternating generalized expectation-maximization (SAGE) and a clustering algorithm. These estimates allow an analysis of the variations of the channel properties due to the presence of the body. Notably, we observe strong modifications of the spatial characteristics of the channel. The delay spread is characterized as a function of the body orientation and the antenna position on the body. In addition, a modeling of the angles-of-arrival based on a Laplacian distribution is given. A cluster modeling is provided along with parameters. Finally, the part of diffuse multipath components not detected by SAGE algorithm is analyzed in function of the communication scenario.