Abstract— Channel estimation and synchronization are crucial problems in coherent Ultra wideband (UWB) systems. We develop a new channel estimation scheme that can further improve the estimation performance compared with the traditional Maximum-Likelihood estimator by using the second order statistic of the fading channel. The new scheme is analyzed theoretically and the performance improvement is evaluated by a computer simulation using IEEE 802.15.3a ultra-wideband channel models. Theoretical analysis and simulation results show that the new scheme improves the estimation performance of channel gains significantly at high noise power regime.