This paper introduces a Single car- rier Ultra-wideband (SC-UWB) transmission scheme with Mean square error (MSE) channel estimation. Speci¯cally, the scheme employs Direct sequence Binary phase shift keying (DS-BPSK) to support high to moderate data rate applications which di®erentiates from Multi-band Orthog- onal frequency division multiplexing (MB-OFDM) and Im- pulse radio (IR) UWB systems. Simulation results show that, with baseband time-frequency signal processing al- gorithms, the Bit error rate (BER) performance of the SC-UWB system over the IEEE 802.15.3a UWB Chan- nel model III (CM3) is about 10¡5 at Eb=N0 of 10.5dB. Moreover, the SC-UWB system exhibits a low power con- sumption and low implementation complexity due to its low Peak-to-average ratio (PAR) and modulation charac- teristics. It is evident that the scheme will be a good can- didate for short range communications, especially for low power and low cost applications such as mobile terminals.