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

摘要

This paper investigates the impact of timing jitter on direct sequence ultra wideband (DS-UWB) system in additive white Gaussian noise (AWGN) and multipath environment. A Rake receiver is used to capture the signal at the receiving end. Timing jitter with both uniform and Gaussian distribution is simulated in the template generator of the Rake receiver. Investigation is performed for both Ordinary and Optimum Rake, each with All Rake and Selective Rake systems. Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) methods are also used for these Rake systems with timing jitter. The results are displayed in the form of bit error rate (BER) in accordance to varying root mean square (RMS) jitter, signal to noise ratio (SNR), and selectively captured path. It is shown that timing jitter has a more significant effect in optimum rake rather than ordinary rake system. Gaussian distributed timing jitter is observed to have a greater impact on the system performance at low RMS jitter. As RMS jitter increases, uniformly distributed timing jitter has a greater impact. At higher SNR with RMS jitter 0.05, Gaussian distributed jitter has a more severe impact. 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 receivers due to its lower system complexity.