Receiver structures for multicarrier UWB systems

Multicarrier UWB (MC-UWB) communication systems use orthogonal UWB pulse trains and multiple sub-channels to achieve reliable high bit rate transmission and spectral efficiency. In a multipath fading channel, MC-UWB systems suffer from inter-channel interference (ICI) because the received sub-carriers arriving via different paths are no longer orthogonal. We study the performance of the optimum multichannel maximum likelihood (MC-ML) receiver for such channels. The complexity of the optimum receiver increases exponentially with the number of sub-carriers. Since the optimum receiver is too complex to be implemented, we also study a single channel Rake receiver with channel information and a noncoherent single channel receiver that requires no channel information. We compare their performance to that of the optimal receiver and that of a pilot assisted scheme for MC-UWB.