An Effective Timing Synchronization Scheme for DHTR UWB Receivers

In performing short-distance, high-data-rate wireless communications using ultra-wideband (UWB) systems, it is necessary to reduce the average transmission power and ensure a fixed synchronization error between the transmitter and receiver ends. Furthermore, to reduce multipath interference, the UWB system should be sometimes implemented using a rake receiver. However, for such receivers, the delay time and attenuation loss over each transmitted route must be known in advance. In the present study, the complexity of rake receivers with a large number of “fingers” is reduced by means of a delay-hopped transmitted-reference (DHTR) scheme, in which the delayed signal is correlated with the original signal; thereby avoiding the need for a separate template signal. The synchronization performance of the proposed DHTR receiver is analyzed both theoretically and numerically. An effective timing synchronization scheme, designated as “parallel signal acquisition with shared looped delay-line” (PS-SLD), is then proposed. The simulation results show that for multipath environments with a single user, the proposed synchronization scheme achieves a higher detection probability and a lower normalized mean square error (MSE) than the traditional timing dirty templates (TDT) algorithm.