Prototyping and measurements for a LiFi system

Proceedings of: Sensor Array and Multichannel Signal Processing Workshop (SAM), 2016 IEEEWe are witnessing a revolution in wireless technology where Light Fidelity (LiFi) emerges as one potential candidate. In this paper we present a LiFi prototype that allows us to verify the feasibility of deploying this technology. The prototype is based on two Spartan 6 FPGAs and uses a Light Emitting Diode (LED) to transport the information through amplitude changes of the light. The receiver uses a low dark current PIN photodiode. We describe the system design, the receiver algorithms and the measurement set-up. We present some measurements where in a Line of Sight (LOS) channel the received pulses are shown to match the transmitted ones.This work has been partly funded by the Company UVAX-Concepts, within Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2013-2016 (TSI-100502-2013-024) and ELISA project (TEC2014-59255-C3-3-R). The authors would like to thank this support

Design and implementation of an uplink connection for a light-based IoT node

Abstract. In the wake of soaring demand for shrinking radio frequency (RF) spectrum, light-fidelity (LiFi) has been heralded as a solution to accommodate resources for future communication networks. Infrared (IR) and visible light communication (VLC) are meant to be used within LiFi because of numerous advantages. By combining the paradigm of internet of things (IoT) along with LiFi, light-based IoT (LIoT) emerges as a potential enabler of future 6G networks. With tremendous number of interconnected devices, LIoT nodes need to be able to receive and transmit data while being energy autonomous. One of the most promising clean energy sources comes from both natural and artificial light. In addition to providing illumination and energy, light can also be utilized as a robust information carrier. In order to provide bidirectional connectivity to LIoT node, both downlink and uplink have to be taken into consideration. Whereas downlink relies on visible light as a carrier, uplink approach can be engineered freely within specific requirements. With this in mind, this master’s thesis explores possible solutions for providing uplink connectivity. After analysis of possible solutions, the LIoT proof-of-concept was designed, implemented and validated. By incorporating printed solar cell, dedicated energy harvesting unit, power-optimised microcontroller unit (MCU) and light intensity sensor the LIoT node is able to autonomously transmit data using IR

The Impact of Solar Irradiance on Visible Light Communications

This paper aims to address the perception that visible light communication (VLC) systems cannot work under the presence of sunlight. A complete framework is presented to evaluate the performance of VLC systems in the presence of solar irradiance at any given location and time. The effect of solar irradiance is investigated in terms of degradations in signal to noise ratio, data rate, and bit error rate. Direct current (DC) optical orthogonal frequency division multiplexing is used with adaptive bit and energy loading to mitigate DC wander interference and low-frequency ambient light noise. It was found that reliable communication can be achieved under the effect of solar irradiance at high-speed data rates. An optical bandpass blue filter is shown to compensate for half of the reduced data rate in the presence of sunlight. This work demonstrates data rates above 1 Gb/s of a VLC link under strong solar illuminance measured at 50350 lux in clear weather conditions

Digitalization of Retail Stores using Bluetooth Low Energy Beacons

This thesis explores the domains of retail stores and the Internet of Things, with a focus on Bluetooth Low Energy beacons. It investigates how one can use the technology to improve physical stores, for the benefit of both the store and the customers. It does this by going through literature and information from academia and the relevant industry. Additionally, an interview with an expert in the retail domain is conducted, and a survey consisting of a series of interviews and questionnaire with what can be considered experts in the IT domain. A prototype app called Stass is developed, the app demonstrates some of the usages of the technology and is also used for evaluating the performance of the beacons.Masteroppgave i informasjonsvitenskapINFO39

On the Road to 6G: Visions, Requirements, Key Technologies and Testbeds

Fifth generation (5G) mobile communication systems have entered the stage of commercial development, providing users with new services and improved user experiences as well as offering a host of novel opportunities to various industries. However, 5G still faces many challenges. To address these challenges, international industrial, academic, and standards organizations have commenced research on sixth generation (6G) wireless communication systems. A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc. Although ITU-R has been working on the 6G vision and it is expected to reach a consensus on what 6G will be by mid-2023, the related global discussions are still wide open and the existing literature has identified numerous open issues. This paper first provides a comprehensive portrayal of the 6G vision, technical requirements, and application scenarios, covering the current common understanding of 6G. Then, a critical appraisal of the 6G network architecture and key technologies is presented. Furthermore, existing testbeds and advanced 6G verification platforms are detailed for the first time. In addition, future research directions and open challenges are identified for stimulating the on-going global debate. Finally, lessons learned to date concerning 6G networks are discussed

Noise and Bandwidth Consideration in Designing Op-Amp Based Transimpedance Amplifier for VLC

In a visible light communication (VLC) system, there are many modules involved. One of the important modules is Transimpedance Amplifier (TIA) that resides in the analog front-end receiver (Rx-AFE). TIA is responsible for performing signal conversion from current signal, which is provided from the photodiode (PD) to voltage signal. It is the reason why the TIA should be operating in low noise condition and wide bandwidth of frequency. These will enable a flexible coverage of the VLC system in performing its signal processing. Hence, in this research, we provide considerations of the noise and frequency bandwidth analysis in designing TIA to cope with the required design specification of a VLC system

State of the Art, Trends and Future of Bluetooth Low Energy, Near Field Communication and Visible Light Communication in the Development of Smart Cities

The current social impact of new technologies has produced major changes in all areas of society, creating the concept of a smart city supported by an electronic infrastructure, telecommunications and information technology. This paper presents a review of Bluetooth Low Energy (BLE), Near Field Communication (NFC) and Visible Light Communication (VLC) and their use and influence within different areas of the development of the smart city. The document also presents a review of Big Data Solutions for the management of information and the extraction of knowledge in an environment where things are connected by an “Internet of Things” (IoT) network. Lastly, we present how these technologies can be combined together to benefit the development of the smart city

Development and characterisation of error functions in design

As simulation is increasingly used in product development, there is a need to better characterise the errors inherent in simulation techniques by comparing such techniques with evidence from experiment, test and inservice. This is necessary to allow judgement of the adequacy of simulations in place of physical tests and to identify situations where further data collection and experimentation need to be expended. This paper discusses a framework for uncertainty characterisation based on the management of design knowledge leading to the development and characterisation of error functions. A classification is devised in the framework to identify the most appropriate method for the representation of error, including probability theory, interval analysis and Fuzzy set theory. The development is demonstrated with two case studies to justify rationale of the framework. Such formal knowledge management of design simulation processes can facilitate utilisation of cumulated design knowledge as companies migrate from testing to simulation-based design

Designing, Building, and Characterizing RF Switch-based Reconfigurable Intelligent Surfaces

In this paper, we present our experience designing, prototyping, and empirically characterizing RF Switch-based Reconfigurable Intelligent Surfaces (RIS). Our RIS design comprises arrays of patch antennas, delay lines and programmable radio-frequency (RF) switches that enable passive 3D beamforming, i.e., without active RF components. We implement this design using PCB technology and low-cost electronic components, and thoroughly validate our prototype in a controlled environment with high spatial resolution codebooks. Finally, we make available a large dataset with a complete characterization of our RIS and present the costs associated with reproducing our design