  Bit error rate (BER) performance of impulse radio Ultra-Wideband (UWB)
systems in the presence of intrasymbol interference, inter-symbol interference,
multiuser interference and addictive white Gaussian noise (AWGN) is presented
in this paper. By analyzing the indoor office LOS channel model defined by IEEE
802.15.4a Task Group and deducing the variance for intra-symbol interference
(IASI), inter-symbol interference (ISI) and multiuser interference (MUI), the
system BER expression is obtained and verified by MATLAB simulations. Through
comparing the simulation results with and without intra-symbol interference,
the conclusion that intra-symbol interference cannot be neglected is
drawn-moreover, such interference will significantly decrease performance of
UWB based wireless sensor networks (WSN). Then, the BER performance of UWB
systems in multiuser environment is also analyzed and analysis results show
that multiuser interference will further worsen the transmission performance of
UWB systems.
