Performance Analysis of Ble 5.1 New Feature Angle of Arrival for Relative Positioning

Abstract

Abstract. The official release of Bluetooth Core Specification, version 5.1 in 2019, provides a new feature for direction determination. It introduces a fine-grained angle measurement capability including Angle of Arriva (AoA) and Angle of Departure, which is deemed essential to the development of Internet of Things applications for localization or relative positioning within the area where Global Navigation Satellite System signals cannot be received. In this paper, we set up a series of experiments to empirically evaluate the direction of the Bluetooth Low Energy transmitter based on the AoA mechanism using the commercialised equipment. The experimental evaluation is performed, for the first time to date, under four different testing environments and other various conditions to inspect the fidelity of angle measurement against the high accuracy given in the specifications. In details, an ideal environment (i.e., anechoic chamber with no multi-path effect), an underground mine, an open area and a typical office area are all tested comprehensively. The experimental results reveal that the ideal environment has the best performance with the minimum error and conforms with the provided datasheet. The worst case occurs on the data collected from the office area. We also find a regular pattern always showing up repeatedly on the error plots based on the measurement results and scrutinize the truthfulness of this rule by adding more innumerable tests conducted in the office. Our results show that the performance of accuracy does depend on the data channel selection due to the multi-path effect.

BmmW: A DNN-Based Joint BLE and mmWave Radar System for Accurate 3D Localization

“…To improve accuracy, direction-finding enhancements were introduced in the BLE 5.1 specifications, namely support for Angle of Arrival (AoA) and Angle of Departure (AoD). Several researchers have conducted empirical studies to evaluate the accuracy of BLE's AoA technique [24], [25], but mainly for static targets and using only a limited number of tested locations. Recently, Pau et al [26] have used a hybrid solution based on both RSSI and AoA information that results in an average distance error of 0.7 m. However, the authors tested only a few locations and did not describe in detail how these were chosen nor the impact of dense multipath on RSSI-based measurements.…”

“…To improve the accuracy of the AoA technique, researchers have proposed algorithms based on non-linear recursive least square and unscented Kalman filters to reduce multipath and antenna switching errors [27]. Unfortunately, the choice of channel greatly impacts the direction-finding techniques [24], [25], and the angular error spreads more at lower frequencies [5]. An empirical study using softwaredefined radios demonstrated the effectiveness of the AoA technique in achieving sub-metre accuracy when tracking moving targets [5]; however, measurements were carried out in an outdoor environment with few multipath reflections, and information from several packets was averaged to obtain the reported accuracy.…”

Location Accuracy Optimization in Bluetooth Low Energy (BLE) 5.1-Based Indoor Positioning System (IPS)—A Machine Learning Approach

“…The location accuracy that can be expected from BLE 5.0 is about 2-5m [1,2]. In 2019, BLE 5.1 was released which included new metrics for positioning, Angle of Arrival (AoA) and Angle of Departure (AoD), that enables Direction Finding feature 2 within BLE devices [3]. With this new addition to the newer BLE 5.1 version, location accuracy down to below 1.0m, known as sub-meter level accuracy can be expected [1,4].…”

“…DT and GBA are tested against online training dataset.2. TDT and ODT machine learning models are trained 3…”