Multipath energy combining for fast UWB acquisition without channel knowledge

In this paper, we study the effectiveness of the multipath energy combining for the coarse acquisition of UWB signals. The performances of different detectors, including single pulse correlator (SPC), energy detector (ED), and transmittedreference (TR), are derived and compared in terms of the mean acquisition time (MAT) and the false acquisition rate (FAR) using flow graph analysis in a two-step random search framework. The results show that both the ED and the TR can achieve a lower acquisition time than the SPC under the same FAR constraint due to their multipath energy combining capabilities. Simulation results also reveal that the ED scheme is more vulnerable to multiuser interference than the TR and the SPC schemes.