Digital Beamforming Techniques for Passive UHF RFID Tag Localization

Radio-frequency identification (RFID) technology is on the way to substitute traditional bar codes in many fields of application. Especially the availability of passive ultra-high frequency (UHF) RFID transponders (or tags) in the frequency band between 860 MHz and 960 MHz has fostered the global application in supply chain management. However, the full potential of these systems will only be exploited if the identification of objects is complemented by accurate and robust localization. Passive UHF RFID tags are cost-effective, very small, extremely lightweight, maintenancefree, rugged and can be produced as adhesive labels that can be attached to almost any object. Worldwide standards and frequency regulations have been established and a wide infrastructure of identification systems is operated today. However, the passive nature of the technology requires a simple communication protocol which results in two major limitations with respect to its use for localization purposes: the small signal bandwidth and the small allocated frequency bandwidth. In the presence of multipath reflections, these limitations reduce the achievable localization accuracy and reliability. Thus, new methods have to be found to realize passive UHF RFID localization systems which provide sufficient performance in typical multipath situations. In this thesis, an enhanced transmission channel model for passive UHF RFID localization systems has been proposed which allows an accurate estimation of the channel behaviour to multipath. It has been used to design a novel simulation environment and to identify three solutions to minimize multipath interference: a) by varying the channel interface parameters, b) by applying diversity techniques, c) by installation of UHF absorbers. Based on the enhanced channel model, a new method for tag readability prediction with high reliability has been introduced. Furthermore, a novel way to rate the magnitude of multipath interference has been proposed. A digital receiver beamforming localization method has been presented which uses the Root MUSIC algorithm for angulation of a target tag and multipath reducing techniques for an optimum localization performance. A new multiangulation algorithm has been proposed to enable the application of diversity techniques. A novel transmitter beamforming localization approach has been presented which exploits the precisely defined response threshold of passive tags in order to achieve high robustness against multipath. The basic technique has been improved significantly with respect to angular accuracy and processing times. Novel experimental testbeds for receiver and transmitter beamforming have been designed, built and used for verification of the localization performance in real-world measurements. All the improvements achieved contribute to an enhancement of the accuracy and especially the robustness of passive UHF RFID localization systems in multipath environments which is the main focus of this researc

Sensors and Systems for Indoor Positioning

This reprint is a reprint of the articles that appeared in Sensors' (MDPI) Special Issue on “Sensors and Systems for Indoor Positioning". The published original contributions focused on systems and technologies to enable indoor applications

Recent Advances in Indoor Localization Systems and Technologies

Despite the enormous technical progress seen in the past few years, the maturity of indoor localization technologies has not yet reached the level of GNSS solutions. The 23 selected papers in this book present the recent advances and new developments in indoor localization systems and technologies, propose novel or improved methods with increased performance, provide insight into various aspects of quality control, and also introduce some unorthodox positioning methods

Radio-Frequency Based Location Service

À medida que a concorrência entre os retalhistas aumenta, uma forma de ganhar vantagem em relação aos outros é compreender melhor o comportamento dos clientes dentro das lojas. No entanto, rastrear a localização exata e o caminho que cada cliente faz, desde que este entra na loja até que chega à caixa de pagamento não é uma tarefa fácil. O ambiente pelo qual os clientes se deslocam é bastante complexo e com imensas variações, devido à quantidade de pessoas e dispositivos presentes, trazendo um grande desafio ao tentar obter a suas localizações. A procura por melhores abordagens de localização indoor gera muita pesquisa e desenvolvi- mento. A localização sem fios baseada em AoA é uma técnica bastante promissora que permite identificar a localização de cada indivíduo com alta precisão, aproveitando o uso comum de dis- positivos móveis. Estes sistemas de localização baseados em radiofrequência necessitam de estar cimentados com bases que evitem grandes infraestruturas e investimentos, uma vez que pode ser possível implementar outros sistemas com mais fiabilidade e maior precisão, mesmo apresentando uma maior complexidade. Apesar dessas restrições, a exatidão das previsões da localização é essencial para avaliar qual a melhor solução. A Connected Mobile Experiences (CMX) dos pontos de acesso (AP) da Cisco funciona nestas circunstâncias, cumprindo todos os requisitos necessários, fornecendo a localização de todos os clientes por meio de chamadas a uma API. A localização de cada alvo é profundamente investigada para melhorar o modelo. Estas me- lhorias são feitas avaliando a influência do ambiente nas previsões feitas, de forma a reduzir o erro na determinação da localização. Foram executados testes empíricos para medir os valores de erro comparando as localizações de referência com as previsões feitas pelo modelo. Além disso, foi testada a precisão de diferentes tipos de normas Wi-Fi (Wi-Fi 4, Wi-Fi 5, Wi-Fi 6), e como esperado, a utilização da norma mais recente, WIFI 6, apresenta melhores resultados comparati- vamente às suas antecedentes. Uma melhor compreensão dos clientes acrescenta valor comercial aos retalhistas, provocando um impacto direto na organização da loja e na eficiência dos anúncios de produtos específicos. Por outro lado, os consumidores são a principal razão para que este estudo seja feito, tentando sempre melhorar a sua experiência de compra sem que se apercebam disso.The European automobile sector contributes over 7% of the EU GDP, it has an important role in the Europe's innovation, employment and economic growth, but it's being shaped by three main factors. Firstly, the rise of shared access and autonomous vehicles changed the mobility ecosystem and altered how consumers conceive buying and owning a car. Secondly, worldwide car sales have been declining. Even though we're currently in a moment of financial recovery, the drops in sales hit record numbers since the economic crisis. This drop reflects the growing apprehension in committing to such a costly purchase, as well as a diminished confidence in the automotive manufacturers. Thirdly, since vehicles are becoming more and more advanced, the complexity of information is also increasing, this causes difficulties in explaining new features to the clients. To reduce the impact of these factors we could provide the vehicle information in a more involving way by using Augmented Reality (AR) to create a more engaging dealership expe- rience. To do so, we analyze its viability in comparison with other types of interactions and design, develop and evaluate prototypes solutions with increased usability. Augmented Reality was chosen because it blends the components of a digital world into a person's perception of the reality, allowing for more involving experiences. It also generates of new ways to display and interact with information while still being able to create a human connection with the brand, the dealership and the product. It's expected that the solution proposed will allow for better content marketing by distributing valuable, relevant, and consistent content to attract and retain more costumers, ultimately increasing the number of car sales

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Proceedings of the 3rd International Conference on Models and Technologies for Intelligent Transportation Systems 2013

Challenges arising from an increasing traffic demand, limited resource availability and growing quality expectations of the customers can only be met successfully, if each transport mode is regarded as an intelligent transportation system itself, but also as part of one intelligent transportation system with “intelligent” intramodal and intermodal interfaces. This topic is well reflected in the Third International Conference on “Models and Technologies for Intelligent Transportation Systems” which took place in Dresden 2013 (previous editions: Rome 2009, Leuven 2011). With its variety of traffic management problems that can be solved using similar methods and technologies, but with application specific models, objective functions and constraints the conference stands for an intensive exchange between theory and practice and the presentation of case studies for all transport modes and gives a discussion forum for control engineers, computer scientists, mathematicians and other researchers and practitioners. The present book comprises fifty short papers accepted for presentation at the Third Edition of the conference. All submissions have undergone intensive reviews by the organisers of the special sessions, the members of the scientific and technical advisory committees and further external experts in the field. Like the conference itself the proceedings are structured in twelve streams: the more model-oriented streams of Road-Bound Public Transport Management, Modelling and Control of Urban Traffic Flow, Railway Traffic Management in four different sessions, Air Traffic Management, Water Traffic and Traffic and Transit Assignment, as well as the technology-oriented streams of Floating Car Data, Localisation Technologies for Intelligent Transportation Systems and Image Processing in Transportation. With this broad range of topics this book will be of interest to a number of groups: ITS experts in research and industry, students of transport and control engineering, operations research and computer science. The case studies will also be of interest for transport operators and members of traffic administration

IoT Applications Computing

The evolution of emerging and innovative technologies based on Industry 4.0 concepts are transforming society and industry into a fully digitized and networked globe. Sensing, communications, and computing embedded with ambient intelligence are at the heart of the Internet of Things (IoT), the Industrial Internet of Things (IIoT), and Industry 4.0 technologies with expanding applications in manufacturing, transportation, health, building automation, agriculture, and the environment. It is expected that the emerging technology clusters of ambient intelligence computing will not only transform modern industry but also advance societal health and wellness, as well as and make the environment more sustainable. This book uses an interdisciplinary approach to explain the complex issue of scientific and technological innovations largely based on intelligent computing

Reduction of multipath propagation influences at PoA positioning using uniform circular array antennas analyses based on measurements in vehicular scenarios: Analyses based on measurements in vehicular scenarios

In today's Intelligent Transportation Systems (ITS) accurate positioning information plays an increasing role. The automated registration and counting of passengers in public transportation and ticketing systems are based on the localization of passengers. Techniques leant on wireless sensor networks (WSNs) are an increasingly popular approach for estimating positions in a wide area of applications. Indoor environments like vehicular scenarios have strong multipath characteristics. Therefore, the WSN localization is limited by shadowing, reflexions, interferences and especially multipath propagation. The present paper deals with the application of special beam forming antennas and uniform circular arrays (UCAs) at a mobile sensor node for localization in vehicular scenarios to reduce the multipath propagation influences

Actas da 10ª Conferência sobre Redes de Computadores

Universidade do MinhoCCTCCentro AlgoritmiCisco SystemsIEEE Portugal Sectio