New TOA Estimators within Energy-Based Receivers under Realistic UWB Channel Statistics

The Impulse Radio - Ultra Wideband (IR-UWB) technology, which benefits from unprecedented ranging capabilities through precise Time of Arrival (TOA) estimation, is now widely considered as a credible solution for Location and Tracking (LT) applications in Wireless Sensor Networks (WSN). In this context, low-complexity receiver architectures such as Energy Detectors (ED) have been favored for the past years. Recent methods have also been proposed to determine ED thresholds for optimal leading-edge detection under simplified channel assumptions. Nevertheless, more realistic indoor multipath profiles still make threshold-based TOA estimation challenging with such receivers. In this paper, we present two new Bayesian TOA estimators that rely on the overall energy profile available at the output of the ED, as well as on realistic channel statistics (typically that of the IEEE 802.15.4a standard). Simulation results are provided for performance comparison with two popular threshold-based estimators, showing the robustness of the new methods at practical Signal to Noise Ratio (SNR) values.