UWB Channel Estimation: Design and Performance Evaluation

In this paper, we investigate channel estimation for a single-carrier direct-sequence ultra-wideband (DS-UWB) system based on the realistic IEEE P802.15.3a UWB channel model. In the preamble of each packet, pilot symbols are spread by the pseudorandom acquisition code and sent through the channel. At the receiver, the well known sliding window algorithm is applied to estimate the multipath channel coefficients. For channel models CM1 through CM4, we determine the length of the acquisition code to mitigate the impact of intersymbol interference on channel estimation with negligible redundant search space. We also develop a generic approach to design the pilot sequence length based on the UWB channel statistics. Furthermore, a general analytical framework is developed to accurately evaluate the symbol error rate performance with imperfect Rake tap coefficients. Simulation results are shown to verify the theoretical evaluation