Single-Anchor Positioning: Multipath Processing With Non-Coherent Directional Measurements

Abstract

High-accuracy indoor radio positioning can be achieved by using (ultra) wideband (UWB) radio signals. Multiple fixed anchor nodes are needed to compute the position or alternatively, specular multipath components (SMCs) extracted from radio signals can be exploited. In this work, we study a multipath-based, single-anchor positioning system that acquires directional measurements non-coherently. These non-coherent measurements can be obtained, e.g., from a single-chain mm-wave transceiver with analog beam steering or from a low-complexity ultra-wideband transceiver with switched directional antennas. The directional antennas support the separation of SMCs and the suppression of the undesired diffuse multipath component (DMC) with the benefit that the required signal bandwidth can be drastically reduced. The paper analyzes the Cramér-Rao lower bound (CRLB) on the position estimation error to gain insight in the influence of the system design parameters as well as the impact of the DMC on the position error. The CRLB is compared between the non-coherent antenna setup, a conventional array with coherent processing, and a single-antenna setup. A maximum-likelihood position estimation algorithm is formulated. Its performance is evaluated with synthetically generated data as well as with UWB measurements. We show that the accuracy and robustness are significantly improved due to the processing of angular information. Analyzing the measured data for a line-of-sight link, the median error decreases from 22 down to 7 cm, the measurements better than 20 cm increase from 46 to 95 %, and outliers above 50 cm reduce from 12 to 0 %. INDEX TERMS Radio positioning, single-anchor, Fisher information, position error bound, directional antenna, multipath component, non-coherent array processing.

A Review of Device-Free Indoor Positioning for Home-Based Care of the Aged: Techniques and Technologies

“…Regardless of the localization method used, the key to the localization method is the need for one or more reference points with known coordinates and the determination of the spatial location relationship between the unknown nodes and the known reference points [57]. The localization process can be divided into two parts measuring the position information and determining the target position based on the measurement information [58]. The main positioning method is shown in Fig.…”

Calibration-Free Single-Anchor Indoor Localization Using an ESPAR Antenna

“…Position estimation was performed based on a DoA fingerprinting approach using spatial spectrum measurements, where the measured spatial spectrum is compared with the set of training data using the Pearson correlation coefficients. In [ 37 ], the authors propose a multipath-based, single-anchor positioning system, which non-coherently acquires directional measurements by exploiting specular multipath components.…”

Positioning and Tracking with ODE-LSTM Algorithm for Emerging Smart Rail Systems

“…Several methods have been proposed to solve the problem of target tracking in NLOS environments as well, such as utilizing the hybrid of LOS and NLOS for tracking [22], [23], [24], multiple BS assisted tracking [25], and single BS tracking based on multiple paths [26], [27]. The example hybrid usage of LOS and NLOS channels is introduced in [24], [42], which uses NLOS paths assisted LOS channel to track UE and utilize enhanced Kalman Filter (EKF) for estimation.…”