Robust adaptive channel estimation and multiuser detection for ultra wideband in a realistic indoor channel

A robust Kalman filter-based adaptive multiuser receiver is proposed for channel estimation and multiuser detection of ultra wideband (UWB) systems in a realistic indoor channel. A state space stochastic model is developed to describe the dynamics of the UWB multiuser transmission systems. A robust Kalman filter is employed to estimate the channel parameters. In the tracking mode with consideration of channel estimation errors, the proposed robust Kalman filter-based adaptive multiuser decision-feedback equalizer can significantly reduce effects of the multiple access interference (MAI) from the other users and the inter-symbol interference (ISI) in the UWB channel. Simulation results illustrate that performance of the proposed robust adaptive channel estimation works well in a realistic UWB channel. Using the proposed robust channel estimator, the performance of the proposed UWB multiuser detector almost achieves the same bit error rate (BER) as that with actual UWB channel cases, and outplay than that of the conventional RAKE receiver and single-stage parallel interference cancellation (PIC) detector for UWB systems.