A preprocessing algorithm of ultra-wideband signal for space-time focusing transmission

Ultra-wideband (UWB) signal has fine time resolution and can resolve a large amount of multipath in densely scattered environments. Exploiting these features, UWB systems can accomplish space-time focusing transmission. At the focused spot there will exhibit an energy peak, while in other places very weak interference will be induced. The space-time focusing transmission can not only enable the use of simple receiver structure, but also enhance the coexistence capability of UWB systems with the legacy narrowband systems. In this paper, a novel preprocessing method is proposed for multiuser UWB systems. By filtering the transmitted signal, the received signal at the focused time can be sampled without intersymbol interference and multiuser interference. Moreover, the interference to narrowband users can also be avoided.