An Enhanced Indoor Positioning Technique Based on a Novel Received Signal Strength Indicator Distance Prediction and Correction Model (original) (raw)

A new method for improving Wi-Fi-based indoor positioning accuracy

Wi-Fi and smartphone based positioning technologies are play-ing a more and more important role in Location Based Service (LBS) industries due to the rapid development of the smartphone market. However, the low positioning accuracy of these technologies is still an issue for indoor positioning. To ad-dress this problem, a new method for improving the indoor posi-tioning accuracy was developed. The new method initially used the Nearest Neighbor (NN) algorithm of the fingerprinting meth-od to identify the initial position estimate of the smartphone us-er. Then two distance correction values in two roughly perpen-dicular directions were calculated by the path loss model based on the two signal strength indicator (RSSI) values observed. The errors from the path loss model were eliminated by differencing two model-derived distances from the same access point. The new method was tested and the results compared and assessed against that of the commercial Ekahau RTLS system and the NN algorithm. The preliminary results showed that the positioning accuracy has been improved consistently after the new method was applied and the root mean square accuracy improved to 3.3 m from 3.8 m compared with the NN algorithm.

Experimental performance comparison of indoor positioning algorithms based on received signal strength

The work presented here compares the performance of indoor positioning systems suitable for low power wireless sensor networks. Map matching, approximate positioning (weighted centroid) and exact positioning algorithms (least squares) were tested and compared in a small predefined indoor environment. We found that, for our test scenario, weighted centroid algorithms provided the best results. Least squares proved to be completely unreliable when using distances obtained by a propagation model. Major improvements in the positioning error were found when body influence was removed from the test scenario.

An empirical investigation of RSSI-based distance estimation for wireless indoor positioning system

International Journal of Wireless and Mobile Computing, 2015

RSSI-based distance estimation techniques for wireless indoor positioning system require extensive offline calibration to construct propagation model in order to describe the relationship between received signal strength and distance. This paper investigates the accuracy of the well-known propagation models against the measured data at indoor building. From the results, the dual slope model exhibits the best propagation model and it is chosen as the reference for further investigation. The accuracy of dual slope model in distance estimation suffers from the degradation due to the presence of Non Line of Sight (NLOS) condition between mobile station and access point. Therefore, to further improve the accuracy, this paper studies the effect of breakpoint distance and evaluates two simple techniques, running variance and kurtosis index, to identify the NLOS condition. Once the NLOS condition is identified, the best dual slope model can be selected for accurate distance estimation.

Novel Received Signal Strength-Based Indoor Location System: Development and Testing

EURASIP Journal on Wireless Communications and Networking, 2010

A received signal strength-(RSS-)-based indoor location method (ILS) for person/assets location in indoor scenarios is presented in this paper. Theoretical bases of the method are the integral equations relating the electromagnetic (EM) fields with their sources, establishing a cost function relating the measured field at the receivers and the unknown position of the transmitter. The aim is to improve the EM characterization of the scenario yielding in a more accurate indoor location method. Regarding network infrastructure implementation, a set of receivers are deployed through the coverage area, measuring the RSS value from a transmitter node which is attached to the asset to be located. The location method is evaluated in several indoor scenarios using portable measurement equipment. The next step has been the network hardware implementation using a wireless sensor network: for this purpose, ZigBee nodes have been selected. Finally, RSS measurements variability due to multipath effects and nonline-ofsight between transmitter and receiver nodes is mitigated using calibration and a correction based on the difference between the free space field decay law and the measured RSS.

Distance-based Indoor Localization using Empirical Path Loss Model and RSSI in Wireless Sensor Networks

Journal of Robotics and Control (JRC), 2020

Wireless sensor networks (WSNs) have a vital role in indoor localization development. As today, there are more demands in location-based service (LBS), mainly indoor environments, which put the researches on indoor localization massive attention. As the global-positioning-system (GPS) is unreliable indoor, some methods in WSNs-based indoor localization have been developed. Path loss model-based can be useful for providing the power-distance relationship the distance-based indoor localization. Received signal strength indicator (RSSI) has been commonly utilized and proven to be a reliable yet straightforward metric in the distance-based method. We face issues related to the complexity of indoor localization to be deployed in a real situation. Hence, it motivates us to propose a simple yet having acceptable accuracy results. In this research, we applied the standard distance-based methods, which are is trilateration and min-max or bounding box algorithm. We used the RSSI values as the localization parameter from the ZigBee standard. We utilized the general path loss model to estimate the traveling distance between the transmitter (TX) and receiver (RX) based on the RSSI values. We conducted measurements in a simple indoor lobby environment to validate the performance of our proposed localization system. The results show that the min-max algorithm performs better accuracy compared to the trilateration, which yields an error distance of up to 3m. By these results, we conclude that the distance-based method using ZigBee standard working on 2.4 GHz center frequency can be reliable in the range of 1-3m. This small range is affected by the existence of interference objects (IOs) lead to signal multipath, causing the unreliability of RSSI values. These results can be the first step for building the indoor localization system, which low-cost, lowcomplexity, and can be applied in many fields, especially indoor robots and small devices in internet-of-things (IoT) world's today.

Short Range Indoor Distance Estimation by Using RSSI Metric

Istanbul University - Journal of Electrical and Electronics Engineering, 2017

In recent years, indoor localization problem is a highly preferred topic to study. In order to estimate the relative positions of the communication nodes in a localization system, the distance information of each node is required. In this paper, it is aimed to estimate the distances between the nodes by using the received signal strength (RSS) measurements. For an indoor environment, with the RSS based distance estimation methods, the short range distances between the nodes can be estimated by using the Received Signal Strength Indicator (RSSI) measurements taken over a standard wireless communication infrastructure, namely Wi-Fi.

Distance-based Indoor Localization System Utilizing General Path Loss Model and RSSI

2020

Wireless sensor networks (WSNs) have a vital role in indoor localization development. As today, there are more demands in location-based service (LBS), mainly indoor environments, which put the researches on indoor localization massive attention. As the global-positioning-system (GPS) is unreliable indoor, some methods in WSNs-based indoor localization have been developed. Path loss model-based can be useful for providing the power-distance relationship the distance-based indoor localization. Received signal strength indicator (RSSI) has been commonly utilized and proven to be a reliable yet straightforward metric in the distance-based method. We face issues related to the complexity of indoor localization to be deployed in a real situation. Hence, it motivates us to propose a simple yet having acceptable accuracy results. In this research, we applied the standard distance-based methods, which are is trilateration and min-max or bounding box algorithm. We used the RSSI values as the...

RSSI Based Indoor Localization for Smartphone Using Fixed and Mobile Wireless Node

2013 IEEE 37th Annual Computer Software and Applications Conference, 2013

Nowadays with the dispersion of wireless networks, smartphones and diverse related services, different localization techniques have been developed. Global Positioning System (GPS) has a high rate of accuracy for outdoor localization but the signal is not available inside of buildings. Also other existing methods for indoor localization have low accuracy. In addition, they use fixed infrastructure support. In this paper, we present a novel system for indoor localization, which also works well outside. We have developed a mathematical model for estimating location (distance and direction) of a mobile device using wireless technology. Our experimental results on Smartphones (Android and iOS) show good accuracy (an error less than 2.5 meters). We have also used our developed system in asset tracking and complex activity recognition. SECTION I. Introduction Man invented several methods and tools to identify their location a long time ago. Nowadays localization plays a very important role. Various location based services (LBS) has been developed using global positioning system (GPS) for outdoor environment. There are lots of applications where localization is used extensively such as navigation, map generation, complex activity recognition, patient identification, location and tracking in hospitals, child tracking, disaster management, monitoring firefighters, indoor and outdoor navigation for humans or mobile robots, inventory control in factories, anomaly detection, customer interest observation in supermarkets, visitors interest observation in exhibitions, and smart houses [1] [2] [3] [4] [5]. These applications of localization help to solve and improve a variety of real-life problems.

Novel RSSI evaluation models for accurate indoor localization with sensor networks

2014 Twentieth National Conference on Communications (NCC), 2014

In a Wireless Sensor Network (WSN), it is often necessary to know the accurate location of one or more nodes. Various localization methods have been proposed, namely: TDOA, TOA, AOA, GPS and RSSI. All methods except RSSI require added hardware which increases the cost of the WSN. Moreover, the RSSI value of received radio signals is easily available on most sensor nodes. We propose a set of three techniques (mean+filter, mode, mode+filter) for evaluating RSSI for accurate indoor localization. The techniques are developed with the help of rigorous experimental data collected with TelosB nodes. Localization performance with all the models is compared with an existing technique, the mean technique. We assert that the mode-filter technique achieves a 64.86% less error over the mean technique in distance estimation between the transmitter and the receiver, and it has a 21.33% lower error in location estimation.