A Novel Path-Loss Model for UWB Off-Body Propagation

A novel, multi-slope dual breakpoint model for predicting path-loss in ultra-wideband (UWB) off-body communication channels, is proposed. This model is based on real-body measurements, carried out in the frequency range between 3.5GHz-6.5GHz, in an anechoic chamber. New parameters that describe this specific propagation environment are presented and evaluated. Results show that the first breakpoint point angle lies in the lit region of the transmitter and increases exponentially with distance until it rises to its threshold value. Based on this finding the near and far field areas for BAP (body to access point) channels are defined. In addition, newly estimated decay coefficients suggest severe degradation as the receiver moves in between the two critical angles. Finally, techniques for model expansion in two dimensions are discussed.