Design of Rake Receiver for the Multi-path DS-UWB System

This paper studies the Rake receiver for the direct sequence ultra-wideband (DS-UWB) system. SRake receiver and PRake receiver are employed to receive the UWB signal in the indoor dense multi-path UWB channel (IEEE P802.15.TG3a). In order to study how to improve the performance of receivers, different order of Gaussian pulses are discussed firstly. And then, the ML estimation algorithm is used to get the channel timing delay and the weighted value of the Rake receiver. The effect of the performance influenced by different assisted-pilot numbers is discussed with different SNR. Finally, the influence of different branch numbers of the SRake receiver and PRake receiver are given. The simulation results show that the fifth order Gaussian pulse could achieve better performance for the SRake considering the limits of FCC, while the waveforms will not affect the performance greatly for the PRAke receiver. Furthermore, more numbers of assisted-pilot and branches of receiver will improve the system performance. All of these results provide a basis for Rake receiver design of DS-UWB system.