Novel design of tracking process for UWB communication systems

Timing synchronization and tracking process is considered as a major challenge for ultra-wideband (UWB) communication systems. Delay-Locked Loop (DLL) method is widely proposed to maintain the satisfactory synchronization and reduce timing offset error between the received and reference signals. In this paper, we modify the structure of DLL, using a novel control strategy in the communication systems, called Internal Model Control (IMC). Primary simulation results confirm that the proposed DLL is able to achieve satisfactory and accurate tracking in the absence of Doppler Effect. However, the loss of tracking may arise in the presence of Doppler Effect. To solve this problem, we develop the proposed IMC-DLL structure by adding two blocks: model-shifter unit and average filter. The simulation results confirm that the proposed DLL has better transient response, compared with the classical DLL.