Impact of Timing Jitter on Rake Reception of DS- WB Signal over AWGN and Multipath Environment

In this paper, we present the impact of timing jitter on a direct sequence ultra wideband (DS-UWB) system in additive white Gaussian noise (AWGN) and multipath environment. Rake receiver is used to capture the multipath profile. Investigation is performed in ordinary and optimum Rake, each with all Rake (ARake) and selective Rake (SRake). Additionally, the equal gain combining (EGC) maximal ratio combining (MRC) methods are also applied for each combination. We use two types of timing jitter, uniformly distributed and Gaussian distributed, with varying root mean square (RMS) to evaluate the different impacts on the communication system. The bit error rate (BER) of the system is presented corresponding to different parameters such as signal to noise ratio (SNR), RMS jitter and number of selected and combined paths. The simulation results show that optimum Rake is more severely affected by the presence of timing jitter. It is also observed that Gaussian distributed timing jitter has a greater impact to the system than that of the uniformly distributed at low RMS jitter. At higher timing jitter, the performance of ordinary Rake is similar to that of optimum Rake, suggesting that the ordinary Rake is more practical than optimum Rake due to its lower system complexity