| Since the Ultra Wideband (UWB) wireless communication has lots of advantages such as high data transmission rate, low power consumption, high precision location identification and inherently exceptional multipath immunity and so on, it has been the subject of extensive research in the short-range wireless communication area. But there are still some key problems need to be solved before the UWB technology comes into actual use, and one of these key points is synchronization. Since the carrier-less UWB system transmits the base-band, extremely narrow impulses on the sub-nanosecond order directly, the transmitted signals will hide in the noise environment due to the limitation of the signal power. And there exist multi-user interference from the system itself and the other narrowband systems. Accurate synchronization becomes one of the difficult techniques.The subject of this thesis is the synchronization capture technology in UWB. And some realization scheme are proposed and simulated in this thesis. The basic theory of UWB communication is introduced at first. The system model and the modulation technology is then analyzed in detail, also the UWB channel model is discussed. Many synchronization schemes are illustrated and compared in succession. Finally two schemes are proposed, one is the improved Timing with Dirty Templates (TDT) coarse synchronization combined with slide correlation fine synchronization scheme used in the multi-user Direct Sequence spread spectrum UWB (DS-UWB), and the other is the synchronization scheme based on the entire Time Hopping (TH) code in the multi-user TH-UWB system. The simulation results show those two algorithms can capture the synchronization time in the UWB system efficiently. |
