1,683 research outputs found

    Wireless Alliance for Testing Experiment and Research (WALTER) Experts Workshop

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    The purpose of the publication is to describe the WALTER experts workshop and related results and findings. The workshop was conducted in Ispra, Varese, Italy from the 2nd to the 3rd of July 2008 at the European Commission JRC facilities. The workshop was organized as part of the FP7 WALTER project, which has the objective of define a networked test bed laboratory to evaluate UltraWideBand (UWB) technology and equipment. The purpose of WALTER workshop was to present and discuss the current regulatory, standardization and research status of UltraWideBand (UWB) technology with special focus on the definition of requirements, methodologies and tools for UWB measurements and testing. The WALTER workshop had the following main objectives: - Identify the main regulatory and standardization challenges for the adoption of UWB in Europe and the world. Support the identification and resolution of conflicting requirements. - Identify the main challenges in the UWB testing and measurements. Describe how the current industrial and research activity could support the resolution of these challenges. - Discuss the future developments like UWB at 60 GHz and innovative interference and mitigation techniques including Detect And Avoid (DAA). A number of international experts in the UltraWideBand field have been invited to participate to this workshop, to encourage bi-directional communication: in one direction to disseminate the information on WALTER project and its activities, in the other direction to collect the input and feedback on the regulatory and standardization work, industrial activity and research studies.JRC.G.6-Sensors, radar technologies and cybersecurit

    A Quantitative Assessment of the Compatibility of Ultra Wideband with Broadband Wireless Access and Radar Services

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    In July 2008, following a request made by the Radio Spectrum Policy Unit in DG INFSO (Unit B4), a pilot phase of twelve months was agreed with Member States representatives in the Radio Spectrum Committee. During this time the Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has been mandated to provide testing facilities to support the development of Community spectrum legal measures under the Radio Spectrum Decision (676/2002/EC). In the frame of this pilot phase, IPSC-JRC has successfully completed the implementation and extensive testing of both a state-of-the-art laboratory test-bed and a simulation tool, which have been specifically designed for two different coexistence studies. Firstly, the coexistence between broadband wireless access (BWA) and ultra wideband (UWB) services in the 3.5 GHz frequency band; and secondly, the coexistence between radiolocation (i.e. radar) and UWB services in the 3.1-3.4 GHz frequency band. The selection of these two coexistence scenarios is not casual and has been made based on the fact that they have been considered highly relevant in the CEPT-ECC studies on UWB mandated by the European Commission.JRC.G.6-Security technology assessmen

    Ultra-Wideband Radar-Based Activity Recognition Using Deep Learning

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    With recent advances in the field of sensing, it has become possible to build better assistive technologies. This enables the strengthening of eldercare with regard to daily routines and the provision of personalised care to users. For instance, it is possible to detect a person’s behaviour based on wearable or ambient sensors; however, it is difficult for users to wear devices 24/7, as they would have to be recharged regularly because of their energy consumption. Similarly, although cameras have been widely used as ambient sensors, they carry the risk of breaching users’ privacy. This paper presents a novel sensing approach based on deep learning for human activity recognition using a non-wearable ultra-wideband (UWB) radar sensor. UWB sensors protect privacy better than RGB cameras because they do not collect visual data. In this study, UWB sensors were mounted on a mobile robot to monitor and observe subjects from a specific distance (namely, 1.5–2.0 m). Initially, data were collected in a lab environment for five different human activities. Subsequently, the data were used to train a model using the state-of-the-art deep learning approach, namely long short-term memory (LSTM). Conventional training approaches were also tested to validate the superiority of LSTM. As a UWB sensor collects many data points in a single frame, enhanced discriminant analysis was used to reduce the dimensions of the features through application of principal component analysis to the raw dataset, followed by linear discriminant analysis. The enhanced discriminant features were fed into the LSTMs. Finally, the trained model was tested using new inputs. The proposed LSTM-based activity recognition approach performed better than conventional approaches, with an accuracy of 99.6%. We applied 5-fold cross-validation to test our approach. We also validated our approach on publically available dataset. The proposed method can be applied in many prominent fields, including human–robot interaction for various practical applications, such as mobile robots for eldercare.publishedVersio

    A Unified Multi-Functional Dynamic Spectrum Access Framework: Tutorial, Theory and Multi-GHz Wideband Testbed

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    Dynamic spectrum access is a must-have ingredient for future sensors that are ideally cognitive. The goal of this paper is a tutorial treatment of wideband cognitive radio and radar—a convergence of (1) algorithms survey, (2) hardware platforms survey, (3) challenges for multi-function (radar/communications) multi-GHz front end, (4) compressed sensing for multi-GHz waveforms—revolutionary A/D, (5) machine learning for cognitive radio/radar, (6) quickest detection, and (7) overlay/underlay cognitive radio waveforms. One focus of this paper is to address the multi-GHz front end, which is the challenge for the next-generation cognitive sensors. The unifying theme of this paper is to spell out the convergence for cognitive radio, radar, and anti-jamming. Moore’s law drives the system functions into digital parts. From a system viewpoint, this paper gives the first comprehensive treatment for the functions and the challenges of this multi-function (wideband) system. This paper brings together the inter-disciplinary knowledge

    Multicohort cross-sectional study of cognitive and behavioural digital biomarkers in neurodegeneration: the Living Lab Study protocol

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    INTRODUCTION AND AIMS: Digital biomarkers can provide a cost-effective, objective and robust measure for neurological disease progression, changes in care needs and the effect of interventions. Motor function, physiology and behaviour can provide informative measures of neurological conditions and neurodegenerative decline. New digital technologies present an opportunity to provide remote, high-frequency monitoring of patients from within their homes. The purpose of the living lab study is to develop novel digital biomarkers of functional impairment in those living with neurodegenerative disease (NDD) and neurological conditions. METHODS AND ANALYSIS: The Living Lab study is a cross-sectional observational study of cognition and behaviour in people living with NDDs and other, non-degenerative neurological conditions. Patients (n≥25 for each patient group) with dementia, Parkinson's disease, amyotrophic lateral sclerosis, mild cognitive impairment, traumatic brain injury and stroke along with controls (n≥60) will be pragmatically recruited. Patients will carry out activities of daily living and functional assessments within the Living Lab. The Living Lab is an apartment-laboratory containing a functional kitchen, bathroom, bed and living area to provide a controlled environment to develop novel digital biomarkers. The Living Lab provides an important intermediary stage between the conventional laboratory and the home. Multiple passive environmental sensors, internet-enabled medical devices, wearables and electroencephalography (EEG) will be used to characterise functional impairments of NDDs and non-NDD conditions. We will also relate these digital technology measures to clinical and cognitive outcomes. ETHICS AND DISSEMINATION: Ethical approvals have been granted by the Imperial College Research Ethics Committee (reference number: 21IC6992). Results from the study will be disseminated at conferences and within peer-reviewed journals

    Advanced Compact Setups for Passive Intermodulation Measurements of Satellite Hardware

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    (c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] This paper provides the guidelines for the practical development of novel advanced test beds for passive intermodulation(PIM) measurements. The proposed test beds show high performance and are flexible, allowing for the measurement of several PIM signals of different orders, with two or more input carriers. In contrast to classic test beds for satellite hardware, based on the cascaded connection of several elements, an integrated solution involving the minimum number of hardware pieces is proposed. The result is a lower number of flanged interconnections, thus reducing residual PIM level and insertion losses. In addition, return loss degradation and harmful spurious generation in the interconnections are also avoided. Measurement test beds for conducted and radiated PIM, in both transmitted and reflected directions, are discussed, highlighting the benefits and drawbacks of each configuration. Design guidelines for the key components are fully discussed. Illustrative application examples are also reported. Finally, excellent experimental results obtained from low-PIM measurement setups, working from C-band to Ka-band, are shown, thus fully confirming the validity of the proposed configurations.This work was supported in part by the European Space Agency through several research and development contracts, in part by the Ministerio de Economia y Competitividad (Spanish Government) under Project TEC2016-75934-C4-1-R, and in part by the ESA-VSC High Power RF Space Laboratory.Smacchia, D.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M.; Carceller Candau, C.; Ruiz-Garnica, J.; Galdeano, J.... (2018). Advanced Compact Setups for Passive Intermodulation Measurements of Satellite Hardware. IEEE Transactions on Microwave Theory and Techniques. 66(2):700-710. https://doi.org/10.1109/TMTT.2017.2783383S70071066

    System design and validation of multi-band OFDM wireless communications with multiple antennas

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    [no abstract

    Breathfinding: A Wireless Network that Monitors and Locates Breathing in a Home

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    This paper explores using RSS measurements on many links in a wireless network to estimate the breathing rate of a person, and the location where the breathing is occurring, in a home, while the person is sitting, laying down, standing, or sleeping. The main challenge in breathing rate estimation is that "motion interference", i.e., movements other than a person's breathing, generally cause larger changes in RSS than inhalation and exhalation. We develop a method to estimate breathing rate despite motion interference, and demonstrate its performance during multiple short (3-7 minute) tests and during a longer 66 minute test. Further, for the same experiments, we show the location of the breathing person can be estimated, to within about 2 m average error in a 56 square meter apartment. Being able to locate a breathing person who is not otherwise moving, without calibration, is important for applications in search and rescue, health care, and security

    A comparative investigation on performance and which is the preferred methodology for spectrum management; geo-location spectrum database or spetrum sensing

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    A Research Report submitted to the Faculty of Engineering and the Built Environment, University of Witwatersrand, in the partial fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg, 2015.Due to the enormous demand for multimedia services which relies hugely on the availability of spectrum, service providers and technologist are devising a means or method which is able to fully satisfy these growing demands. The availability of spectrum to meet these demands has been a lingering issue for the past couple of years. Many would have it tagged as spectrum scarcity but really the main problem is not how scarce the spectrum is but how efficiently allocated to use is the spectrum. Once such inefficiency is tackled effectively, then we are a step closer in meeting the enormous demands for uninterrupted services. However, to do so, there are techniques or methodologies being developed to aid in the efficient management of spectrum. In this research project, two methodologies were considered and the efficiency of these methodologies in the areas of spectrum management. The Geo-location Spectrum Database (GLSD) which is the most adopted technique and the Cognitive radio spectrum sensing technique are currently the available techniques in place. The TV whitespaces (TVWS) was explored using both techniques and certain comparison based on performances; implementation, practicability, cost and flexibility were used as an evaluation parameter in arriving at a conclusion. After accessing both methodologies, conclusions were deduced on the preferred methodology and how its use would efficiently solve the issues encountered in spectrum managemen
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