BER Sensitivity to Mis-Timing in Correlation-based UWB Receivers

The unique advantages of ultra-wideband (UWB) technology are somewhat encumbered by its stringent timing tolerances. To help to appreciate how critical timing offset estimation is for UWB, the bit-error-rate (BER) sensitivity to timing offsets is investigated in this paper for correlation-based UWB receivers. Focusing on UWB transmissions with time hopping, the BER expressions are derived for various operating conditions and system setups, including AWGN and frequency flat channels, dense multipath fading channels, and various receiver types including sliding correlators and RAKE combiners. It is demonstrated through analyses that time-hopping based multiple-access systems exhibit little tolerance to acquisition errors, while the energy capture capability of a RAKE combiner can be severely compromised by mis-timing.