Energy Normalized Correlation for Signal Acquisition in Power-Control-Absent UWB Networks

This letter presents a novel detection method for signal acquisition in a power-control-absent ultra-wideband (UWB) system where concurrent transmissions are unavoidable. In such a scenario, the conventional single-user detection method which is based on correlating the received signal with a template pulse train suffers from the near-far effect, since the matched-filter sum can easily be overwhelmed by a strong interferer. Our proposal copes with this near-far issue by compensating the correlation result based on the energy in the sliding window. Therefore the energy normalized correlation is sensitive to the existence of a pulse but not to its strength. Our proposal is compared with the conventional method in terms of the probability of faulty acquisition. Simulation results show substantial improvement using our proposed method in an indoor environment with uncontrolled multi-user interference (MUI). We also point out that hybrid time hopping (TH)/direct sequence (DS) UWB systems result in less faulty acquisition than TH UWB systems.