Ultra-wideband communications: From concept to reality

Ultra-Wideband (UWB) radio is an emerging technology with uniquely attractive features inviting major advances in wireless communications, networking, radar, imaging and positioning systems. By its rule-making proposal in 2002, the Federal Communications Commission (FCC) in the US essentially unleashed huge "new bandwidth" (3.6--10.1GHz) at the noise floor, where UWB radios overlaying co-existent RF systems can operate using low-power ultra-short pulses. With similar regulatory processes currently underway in many countries worldwide, industry, government agencies, and academic institutions responded to this FCC ruling with rapidly growing research efforts targeting a host of exciting UWB theory, algorithms and applications.; This research investigation focuses on UWB wireless communications at the physical layer: modeling, estimation and diversity. In a nutshell, the research in this dissertation includes: (i) development of timing synchronization algorithms using dirty templates; (ii) design of an optimal pilot waveform assisted modulation for channel estimation; (iii) derivation of a fully-noncoherent UWB scheme; (iv) study of multi-antenna analog space-time coded UWB system over dense multipath channels to jointly collect space-multipath diversity; and (v) design of multi-access codecs to deal with multi-user interference and narrow-band interference. The findings aspire to impact the basic research and facilitate the transition of UWB from concept to reality.