Biomedical Signal Transmission Using VLC

In biomedical or healthcare application, the implementation of radio communication technologies is frequently flustered by the electromagnetic wave radiations and interference which are harmful to the humanbeings.Hence the transmission of low power (10 to 100?v) Biomedical signals with high degree of accuracy and at very high transmission rate is a challenging job. Thereby we go for a new novel method of transmission of these Biomedical signals using VLC (Visible light communication) technology. White beam light emitting diodes are used as a optical information emitter for efficiently transmitting biomedical data such as patient EEG,CT scan,MRI etc., information. ON/OFF keying modulation is used to modulate the data on to the visible light beam only at the Line of Sight condition. This amplified signal is fed into controller and the Biomedical signal is simulated by interfacing the kit with softwares (Embedded c coded in keil uvision 2.0 and visual basic 6.0).This proposed system has achieved a maximum distance as 10m and the resultant Biomedical signal has SNR greater than 7db with BER of 4.74X10-6.These results proves the excellent reliability and accuracy of proposed system

STUDI AWAL RANCANGAN BIDIRECTIONAL-MULTIUSER PADA VISIBLE LIGHT COMMUNICATION UNTUK APLIKASI DALAM RUANG (INDOOR)

ABSTRAK Visible Light Communication (VLC) atau komunikasi cahaya tampak merupakan teknologi yang sedang on fire selama beberapa tahun ini dan diasumsikan akan terus berlanjut beberapa dekade kedepan karena banyak kelebihan yang ditawarkan, yakni telah tersedia infrastruktur utama berupa lampu penerangan sehingga bersifat cost-effective, bebas lisensi, lebih aman (secure), kecepatan transmisi mencapai GHz, dan tidak memiliki interferensi elektromagnetik. Karena VLC adalah teknologi yang relatif baru, maka standar komunikasinya juga cenderung berkembang ialah standar IEEE 802.15.17 yang terpublikasi akhir tahun 2010 lalu. Standar ini masih mengajukan teknik modulasi dan juga komunikasi pada skenario point-to-point namun sampai saat ini belum mengakomodasi sistem komunikasi dengan skenario Multiuser sekaligus transmisi Bi-directional. Makalah ini merupakan proposal rancangan dalam rangka mendesain sistem VLC secara bi-directional (uplink dan downlink) yang mampu dipakai pada skema multiuser dengan kecepatan bitrate pada downlink mencapai 1 Mbps untuk aplikasi dalam ruang (indoor). Makalah ini terbagi menjadi beberapa bagian pembahasan. Pertama mendefinisikan latar belakang akan dilakukannya sebuah penelitian untuk memperbaiki platform penelitian yang terdahulu dan kontribusinya. Bagian kedua memaparkan penelitian yang relevan beserta state of the art antara penelitian ini dengan lainnya. Bagian ketiga merinci teori dasar. Bagian keempat memaparkan metodologi penelitian dan terakhir adalah batasan masalah dan penutup.   ABSTRACT Visible Light Communication (VLC) is a technology that has been on fire for several years and it is assumed to continue in the next few decades because of the many advantages offered, namely the main infrastructure in the form of lighting so that it is cost-effective, free license, safer (Secure), the transmission speed reaches GHz, and has no electromagnetic interference. Since VLC is a relatively new technology, its communication standards also tend to develop is the IEEE 802.15.17 standard published late 2010. This standard still proposes modulation techniques as well as communications in the point-to-point scenario but until now has not accommodated the communication system with Multiuser scenario as well as Bi-directional transmission. This paper is designed to design a bi-directional (uplink and downlink) VLC system that can be used on multiuser schemes with bitrate speeds downlink of up to 1 Mbps for indoor applications. This paper is divided into several parts of the discussion. First define the background of a research to improve the previous research platform and its contribution. The second part describes the relevant research along with the state of the art between this study and others. The third section details basic theories. The fourth section describes the methodology of research and the last is the limitation of the problem and the conclusion. How to Cite : Fuada, S. (2017). STUDI AWAL RANCANGAN BIDIRECTIONAL-MULTIUSER PADA VISIBLE LIGHT COMMUNICATION UNTUK APLIKASI DALAM RUANG (INDOOR). Jurnal Teknik Informatika, 10(1), 27-36. doi:10.15408/jti.v10i1.6813 Permalink/DOI: http://dx.doi.org/10.15408/jti.v10i1.681

Optical MIMO-OFDM with Generalized LED Index Modulation

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Visible light communications (VLC) is a promising and uncharted new technology for the next generation of wireless communication systems. This paper proposes a novel generalized light emitting diode (LED) index modulation method for multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM)-based VLC systems. The proposed scheme avoids the typical spectrum efficiency losses incurred by time- and frequency-domain shaping in OFDM signals. This is achieved by exploiting spatial multiplexing along with LED index modulation. Accordingly, real and imaginary components of the complex time-domain OFDM signals are separated first, then resulting bipolar signals are transmitted over a VLC channel by encoding sign information in LED indexes. As a benchmark, we demonstrate the performance analysis of our proposed system for both analytical and physical channel models. Furthermore, two novel receiver designs are proposed. Each one is suitable for frequency-flat or selective channel scenarios. It has been shown via extensive computer simulations that the proposed scheme achieves considerably better bit error ratio versus signal-to-noise-ratio performance than the existing VLC-MIMO-OFDM systems that use the same number of transmit and receive units [LEDs and photo diodes (PDs)]. Compared with the single-input single-output (SISO) DC biased optical (DCO)-OFDM system, both spectral efficiency and DC bias can be doubled and removed respectively simply by exploiting a MIMO configuration.European Cooperation in Science and Technology (COST); The Scientific and Technological Research Council of Turkey (TUBITAK) Research; EPSRC under Established Career Fellowshi

Design and performance analysis of optical attocell networks

The exponentially increasing demand for high-speed wireless communications will no longer be satisfied by the traditional radio frequency (RF) in the near future due to its limited spectrum and overutilization. To resolve this imminent issue, industrial and research communities have been looking into alternative technologies for communication. Among them, visible light communication (VLC) has attracted much attention because it utilizes the unlicensed, free and safe spectrum, whose bandwidth is thousand times larger than the entire RF spectrum. Moreover, VLC can be integrated into existing lighting systems to offer a dual-purpose, cost-effective and energy-efficient solution for next-generation small-cell networks (SCNs), giving birth to the concept of optical attocell networks. Most relevant works in the literature rely on system simulations to quantify the performance of attocell networks, which suffer from high computational complexity and provide limited insights about the network. Mathematical tools, on the other hand, are more tractable and scalable and are shown to closely approximate practical systems. The presented work utilizes stochastic geometry for downlink evaluation of optical attocell networks, where the co-channel interference (CCI) surpasses noise and becomes the limiting factor of the link throughput. By studying the moment generating function (MGF) of the aggregate interference, a theoretical framework for modeling the distribution of signal-to-interference-plus-noise ratio (SINR) is presented, which allows important performance metrics such as the coverage probability and link throughput to be derived. Depending on the source of interference, CCI can be classified into two categories: inter-cell interference (ICI) and intra-cell interference. In this work, both types of interference are characterized, based on which effective interference mitigation techniques such as the coordinated multipoint (CoMP), power-domain multiplexing and successive interference cancellation (SIC) are devised. The proposed mathematical framework is applicable to attocell networks with and without such interference mitigation techniques. Compared to RF networks, optical attocell networks are inherently more secure in the physical layer because visible light does not penetrate through opaque walls. This work analytically quantifies the physical-layer security of attocell networks from an information-theoretic point of view. Secrecy enhancement techniques such as AP cooperation and eavesdropper-free protected zones are also discussed. It is shown that compared to AP cooperation, implementing secrecy protected zones is more effective and it can contribute significantly to the network security

Analysis domain model for shared virtual environments

The field of shared virtual environments, which also encompasses online games and social 3D environments, has a system landscape consisting of multiple solutions that share great functional overlap. However, there is little system interoperability between the different solutions. A shared virtual environment has an associated problem domain that is highly complex raising difficult challenges to the development process, starting with the architectural design of the underlying system. This paper has two main contributions. The first contribution is a broad domain analysis of shared virtual environments, which enables developers to have a better understanding of the whole rather than the part(s). The second contribution is a reference domain model for discussing and describing solutions - the Analysis Domain Model

Angular dispersion of radio waves in mobile channels

Multi-antenna techniques are an important solution for significantly increasing the bandwidth efficiency of mobile wireless data transmission systems. Effective and reliable design of these multi-antenna systems requires thorough knowledge of radiowave propagation in the urban environment. The aim of the work presented in this thesis is to obtain a better physical understanding of radiowave propagation in mobile radio channels in order to provide a basis for the improvement of radiowave propagation prediction techniques for urban environments using knowledge from 3-D propagation experiments and simulations combined with space-wave modelling. In particular, the work focusses on: the development of an advanced 3-D mobile channel sounding system, obtaining propagation measurement data from mobile radio propagation experiments, the analysis of measured data and the modelling of angular dispersive scattering effects for the improvement of deterministic propagation prediction models. The first part of the study presents the design, implementation and verification of a wideband high-resolution measurement system for the characterisation of angular dispersion in mobile channels. The system uses complex impulse response data obtained from a novel 3-D tilted-cross switched antenna array as input to an improved version of 3-D Unitary ESPRIT. It is capable of characterising the delay and angular properties of physically-nonstationary radio channels at moderate urban speeds with high resolution in both azimuth and elevation. For the first time, omnidirectional video data that were captured during the measurements are used in combination with the measurement results to accurately identify and relate the received radio waves directly to the actual environment while moving through it. The second part of the study presents the results of experiments in which the highresolution measurement system, described in the first part, is used in several mobile outdoor experiments in different scenarios. The objective of these measurements was to gain more knowledge in order to improve the understanding of radiowave propagation. From these results the dispersive effects in the angular domain, caused by rough building surfaces and other irregular structures was paid particular attention. These effects not only influence the total amount of received power in dense urban environments, but can also have a large impact on the performance and deployment of multi-antenna systems. To improve the data representation and support further data analysis a hierarchical clustering method is presented that can successfully identify clusters of multipath signal components in multidimensional data. By using the data obtained from an omnidirectional video camera the clusters can be related directly to the environment and the scattering effects of specific objects can be isolated. These results are important in order to improve and calibrate deterministic propagation models. In the third part of the study a new method is presented to account for the angular dispersion caused by irregular surfaces in ray-tracing based propagation prediction models. The method is based on assigning an effective roughness to specific surfaces. Unlike the conventional reflection reduction factor for Gaussian surfaces, that only reduces the ray power, the new method also distributes power in the angular domain. The results of clustered measurement data are used to calibrated the model and show that this leads to improved channel representations that are better matched to the real-world channel behavior

Network streaming and compression for mixed reality tele-immersion

Bulterman, D.C.A. [Promotor]Cesar, P.S. [Copromotor