Introduction
A wireless sensor network is a network of cheap and
simple processing autonomous devices (called sensor
nodes) that are spatially distributed in an area of interest
in order to cooperatively monitor physical or environmental
phenomena. Mostly based on non-renewable
resources, such as batteries, wireless sensor networks
(WSNs) call for robust and energy-efficient solutions both
at the software and hardware levels. Undoubtedly, the
IEEE 802.15.4-2011 standard [1] for low-rate wireless personal
area networks (LR-WPANs) is a valuable candidate
for the energy-constrained WSNs. The standard defines
the physical (PHY) and medium access control (MAC)
layers. Among the available PHY options, the impulse
radio ultra-wideband (IR-UWB) PHY (formerly defined in
the IEEE 802.15.4a-2007 standard) has several advanced
properties, such as built-in ranging capabilities, low duty
cycle, low probability of detection, and robustness against
interference, appointing it an ideal information carrier for
communication among the sensor network devices [2].