Enhanced MB-OFDM UWB system with multiple transmit and receive antennas

In this paper, a multi-band space-frequency transmit selection (multi-band SFTS) scheme is proposed for MB-OFDM UWB systems to explore both transmit and receive diversity effectively through multiple transmit and receive antennas without violating the FCC power spectral density (PSD) constraint for UWB. This proposed technique is able to achieve diversity gain in both spatial and frequency domain through selective subcarriers allocation for each transmit antenna at each sub-band based on the channel state information (CSI) obtained from the feedback channels. Meanwhile it applies maximum ratio combining (MRC) to obtain array and diversity gain with multiple receive antennas. Moreover, pre-calibration technique is proposed for SFTS scheme to overcome the mismatch among multiple transmit/receive front-end RF chains. Our simulation result shows that this proposed multi-band SFTS scheme is able to extend the transmission range for UWB-MIMO system and enhance its link robustness over shadowing fading channel.