Maximal operating distance estimation for ranging in IEEE 802.15.4a Ultra Wideband

The IEEE 802.15.4a standard for wireless sensor networks is designed for highly accurate ranging with impulse radio Ultra Wideband (UWB) signals. The standard is designed for coherent and non-coherent (energy detector) receivers, thus the choice of complexity is left to the implementer. In this paper, the maximal operating distance is analyzed for ranging, using a coherent receiver and an energy detector under FCC/EC regulations. The analysis is based on the working points of the receivers and a link budget calculation. The preamble of the standard is defined by several parameters, which influence the allowed FCC transmit power, the free space losses and thus the maximal operating distance. It is shown which code and channel combinations achieve the largest operating distance. The best performance is achieved by using long spreaded codes, where coherent receivers can achieve a maximal operating distance up to several thousand meters and energy detectors up to several hundred meters.