Efficient synchronization-demodulation for UWB ad hoc access: performance analysis and comparisons with RAKE

Synchronization is a performance-critical factor in all communication systems, but becomes particularly challenging in ultra-wideband (UWB) radios due to the ultra-short length of the transmitted pulses. Presence of severe inter-symbol interference (ISI) and multi-user interference (MUI) render the synchronization task even more difficult. The present paper deals with a blind synchronization and demodulation scheme which relies on intermittent transmission of nonzero mean symbols. This transmission pattern enables MUI-and ISI-resilient timing acquisition via energy detection and low-complexity demodulation by correlating the received waveform with a synchronized aggregate template (SAT). The resultant SAT receiver offers distinct advantages over the traditional RAKE and has remarkably low-complexity. Analytical performance evaluation of the novel timing estimator and the SAT demodulator is provided along with comparisons with the RAKE receiver for a single user link without ISI. Simulations confirm the analytical results and corroborate the high potential SAT-based UWB modems have for deployment.