Noise-Based Threshold Ranging Method Using Region-of-Interest in UWB Signals

Abstract

Ultrawideband (UWB) ranging algorithms using thresholding require careful settings that account for multipath richness. Max-peak ratio thresholds are incapable of detecting attenuated first path components (FPCs) or risk triggering on noise. A noise-based threshold is more reliable and robust, but setting this threshold transforms the problem into distinguishing noise from signal. For a limited-length channel impulse response (CIR) from a commercial off-the-shelf (COTS) device, this presents a major challenge. This article presents a novel algorithm to perform this task. We break down the problem into parts, distinguishing a noise-only region on which to base the value of the final threshold from a region-of-interest (RoI) where the FPC can be found. We present a thorough investigation into ranging performance and parameter sensitivity in different environments using both the synthetic and empirical data sources. Our approach achieves on- par performance with the DW1000 on- chip algorithm on an industrial dataset, having an absolute error precision of 37 (90th percentile, P90) and 28 cm [mean absolute error (MAE)]. This is around 5-20 times better than other established low-complexity algorithms such as the max-ratio algorithm (P90: 7.48 m, MAE: 1.73 m) and the leading-edge detection (LDE) algorithm (P90: 4.39 m, MAE: 1.26 m).