452 research outputs found

    A Survey of Positioning Systems Using Visible LED Lights

    Get PDF
    © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.As Global Positioning System (GPS) cannot provide satisfying performance in indoor environments, indoor positioning technology, which utilizes indoor wireless signals instead of GPS signals, has grown rapidly in recent years. Meanwhile, visible light communication (VLC) using light devices such as light emitting diodes (LEDs) has been deemed to be a promising candidate in the heterogeneous wireless networks that may collaborate with radio frequencies (RF) wireless networks. In particular, light-fidelity has a great potential for deployment in future indoor environments because of its high throughput and security advantages. This paper provides a comprehensive study of a novel positioning technology based on visible white LED lights, which has attracted much attention from both academia and industry. The essential characteristics and principles of this system are deeply discussed, and relevant positioning algorithms and designs are classified and elaborated. This paper undertakes a thorough investigation into current LED-based indoor positioning systems and compares their performance through many aspects, such as test environment, accuracy, and cost. It presents indoor hybrid positioning systems among VLC and other systems (e.g., inertial sensors and RF systems). We also review and classify outdoor VLC positioning applications for the first time. Finally, this paper surveys major advances as well as open issues, challenges, and future research directions in VLC positioning systems.Peer reviewe

    RFID Localisation For Internet Of Things Smart Homes: A Survey

    Full text link
    The Internet of Things (IoT) enables numerous business opportunities in fields as diverse as e-health, smart cities, smart homes, among many others. The IoT incorporates multiple long-range, short-range, and personal area wireless networks and technologies into the designs of IoT applications. Localisation in indoor positioning systems plays an important role in the IoT. Location Based IoT applications range from tracking objects and people in real-time, assets management, agriculture, assisted monitoring technologies for healthcare, and smart homes, to name a few. Radio Frequency based systems for indoor positioning such as Radio Frequency Identification (RFID) is a key enabler technology for the IoT due to its costeffective, high readability rates, automatic identification and, importantly, its energy efficiency characteristic. This paper reviews the state-of-the-art RFID technologies in IoT Smart Homes applications. It presents several comparable studies of RFID based projects in smart homes and discusses the applications, techniques, algorithms, and challenges of adopting RFID technologies in IoT smart home systems.Comment: 18 pages, 2 figures, 3 table

    Smartphone indoor positioning based on enhanced BLE beacon multi-lateration

    Get PDF
    In this paper, we introduce a smartphone indoor positioning method using bluetooth low energy (BLE) beacon multilateration. At first, based on signal strength analysis, we construct a distance calculation model for BLE beacons. Then, with the aims to improve positioning accuracy, we propose an improved lateral method (range-based method) which is applied for 4 nearby beacons. The method is intended to design a real-time system for some services such as emergency assistance, personal localization and tracking, location-based advertising and marketing, etc. Experimental results show that the proposed method achieves high accuracy when compared with the state of the art lateral methods such as geometry-based (conventional trilateration), least square estimation-based (LSE-based) and weighted LSE-based

    MIMO Positioning for IMT-Advanced Systems Based on Geometry Approach in NLOS Environments

    Get PDF
    In wireless communications, one of the main problems that deteriorate the accuracy of location and positioning (L&P) estimation is non line of sight (NLOS) propagation. With the advances of multiple input multiple output (MIMO) technology as one of the features of International Mobile Telecommunications-Advanced (IMT-Advanced) systems, it has become feasible to adopt the technology into the mobile location scenario. By exploiting the multipath characteristics of the MIMO system, it is possible to estimate the position of mobile stations (MS) by considering the capability of MIMO to mitigate the effects of non line of sight (NLOS) conditions. In this paper we developed geometric approach by utilizing the advantages of MIMO system and employ the time of arrival (TOA) as range measurements for improving location estimation in various NLOS environments. The performance of the proposed method has been evaluated through computer simulation. The results of our simulation demonstrate the advantages of the proposed algorithm in comparison with the conventional LLS algorithm meeting the Federal Communications Commission (FCC) requirements

    A Framework for UWB-Based Communication and Location Tracking Systems for Wireless Sensor Networks

    Get PDF
    Ultra wideband (UWB) radio technology is nowadays one of the most promising technologies for medium-short range communications. It has a wide range of applications including Wireless Sensor Networks (WSN) with simultaneous data transmission and location tracking. The combination of location and data transmission is important in order to increase flexibility and reduce the cost and complexity of the system deployment. In this scenario, accuracy is not the only evaluation criteria, but also the amount of resources associated to the location service, as it has an impact not only on the location capacity of the system but also on the sensor data transmission capacity. Although several studies can be found in the literature addressing UWB-based localization, these studies mainly focus on distance estimation and position calculation algorithms. Practical aspects such as the design of the functional architecture, the procedure for the transmission of the associated information between the different elements of the system, and the need of tracking multiple terminals simultaneously in various application scenarios, are generally omitted. This paper provides a complete system level evaluation of a UWB-based communication and location system for Wireless Sensor Networks, including aspects such as UWB-based ranging, tracking algorithms, latency, target mobility and MAC layer design. With this purpose, a custom simulator has been developed, and results with real UWB equipment are presented too

    A New Set of Wi-Fi Dynamic Line-Based Localization Algorithms for Indoor Environments

    Get PDF
    Localization is of great importance for several fields such as healthcare and security. To achieve localization, GPS technologies are common for outdoor localization but are insufficient for indoor localization. This is because the accuracy and precision of the users’ indoor locations are influenced by many factors (e.g., multipath signal propagations). As a result, the methodologies and technologies for indoor localization services need to remain continuously under development. A related challenge is the time complexity of the methodologies which impacts the performance of the mobile phones’ limited resources. To address these challenges, a new set of fingerprinting algorithms called Fingerprinting Line-Based Nearest Neighbor (FLBNN) is proposed. Furthermore, the new set is compared to other existing Nearest Neighbor-based algorithms. When the deployment of four access points is considered, the FLBNN algorithms outperform several algorithms in terms of accuracy such as Nearest Neighbor version 2, Nearest Neighbor version 4, and Soft-Range-Limited KNN by approximately 17.1%, 7.8%, and 24.1%; respectively. With regards to precision, the new set of algorithms outperforms Path-Loss-Based Fingerprint Localization (PFL) and Dual-Scanned Fingerprint Localization (DFL) by approximately 7.0% and 60.9%; respectively. Moreover, the FLBNN algorithms have a time complexity of O(t * p) where the term t is the number of deployed centroids and the term p is the number of Path Loss exponents. In addition, the new set of algorithms achieves faster run time compared to those for PFL and DFL. As a result, this Thesis improves the cost and reliability of the indoor location services

    Improvement of mobile trilateration accuracy with modified geo-location techniques.

    Get PDF
    Masters Degree. University of KwaZulu-Natal, Durban.Abstract available in pdf

    A Survey of Positioning Techniques and Location Based Services in Wireless Networks

    Get PDF
    International audiencePositioning techniques are known in a wide variety of wireless radio access technologies. Traditionally, Global Positioning System (GPS) is the most popular outdoor positioning system. Localization also exists in mobile networks such as Global System for Mobile communications (GSM). Recently, Wireless Local Area Networks (WLAN) become widely deployed, and they are also used for localizing wireless-enabled clients. Many techniques are used to estimate client position in a wireless network. They are based on the characteristics of the received wireless signals: power, time or angle of arrival. In addition, hybrid positioning techniques make use of the collaboration between different wireless radio access technologies existing in the same geographical area. Client positioning allows the introduction of numerous services like real-time tracking, security alerts, informational services and entertainment applications. Such services are known as Location Based Services (LBS), and they are useful in both commerce and security sectors. In this paper, we explain the principles behind positioning techniques used in satellite networks, mobile networks and Wireless Local Area Networks. We also describe hybrid localization methods that exploit the coexistence of several radio access technologies in the same region, and we classify the location based services into several categories. When localization accuracy is improved, position-dependant services become more robust and efficient, and user satisfaction increases

    Real-Time Passive Acoustic Tracking of Underwater Vehicles

    Get PDF
    Com o crescente interesse na exploração oceĂąnica, sistemas de localização subaquĂĄtica tĂȘm sido largamente usados pela industria e comunidade cientifica. Neste trabalho foi desenvolvido um sistema de localização acĂșstica passiva em tempo real, com uma topologia idĂȘntica ao do ultra-short baseline. Este sistema calcula a posição a duas dimensĂ”es de uma fonte acĂșstica submersa conhecida, com base na integração de mediçÔes da direção do som ao longo do tempo. O Ăąngulo de chegada da onda sonora Ă© estimado pelo atraso de fase entre os sinais adquiridos por dois hidrofones colocados perto um do outro. Esta configuração permite atenuar as diferenças nos sinais recebidos devidas a perturbaçÔes do canal acĂșstico subaquĂĄtico. Este algoritmo foi implementado em tempo real numa plataforma SoC reconfigurĂĄvel (CPU ARM + FPGA), e validado com ensaios de campo realizados no mar
    • 

    corecore