In this paper, we propose a low complexity multichannel scheme for Ultra Wideband (UWB) channel impulse response estimation. It is mainly based on the finite rate of innovation (FRI) characteristic of UWB channel impulse response, which allows for a sampling frequency much lower than the Nyquist limit. Since the UWB channel is rich in multipaths, the number of samples required results in an unrealistic number of processing channels. Our approach removes this drawback at the price of a moderate increase of the number of pilot pulses. Compared to other schemes presented in the literature, the one proposed in this paper allows reducing the number of processing channels to values appropriate for practical implementation. Moreover, the same approach is used to further reduce the sampling frequency at each channel. The effectiveness of the proposed approach is demonstrated for IEEE 802.15.3a UWB channel estimation in a coherent reception framework.