Doubly Orthogonal Wavelet Packets for Multi-Users Indoor Visible Light Communication Systems

Visible Light Communication (VLC) is a data communication technology that modulates the intensity of the light to transmit the information mostly by means of Light Emitting Diodes (LEDs). The data rate is mainly throttled by the limited bandwidth of the LEDs. To combat, Multi-carrier Code Division Multiple Access (MC-CDMA) is a favorable technique for achieving higher data rates along with reduced Inter-Symbol Interference (ISI) and easy access to multi-users at the cost of slightly reduced compromised spectral efficiency and Multiple Access Interference (MAI). In this article, a multi-user VLC system is designed using a Discrete Wavelet Transform (DWT) that eradicates the use of cyclic prefix due to the good orthogonality and time-frequency localization properties of wavelets. Moreover, the design also comprises suitable signature codes, which are generated by employing double orthogonality depending upon Walsh codes and Wavelet Packets. The proposed multi-user system is simulated in MATLAB software and its overall performance is assessed using line-of-sight (LoS) and non-line-of-sight (NLoS) configurations. Furthermore, two sub-optimum multi-users detection schemes such as zero forcing (ZF) and minimum-mean-square-error (MMSE) are also used at the receiver. The simulated results illustrate that the doubly orthogonal signature waveform-based DWT-MC-CDMA with MMSE detection scheme outperforms the Walsh code-based multi-user system

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

Ultra Wideband

Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

Robust chip-matched myriad filter-based multiuser receiver for impulsive channels

The problem of impulsive noise suppression for direct-sequence code-division multiple-access (DS-CDMA) systems employing multiuser detection in impulsive channels is treated. Prior to the detector, linear chip-matched filter is commonly used for continuous-to-discrete-time conversion. The effects of the non-Gaussian impulsive channel in an asynchronous system are studied by modeling the samples of noise before front-end filtering as a symmetric alpha-stable process. The error probability performance of the linear correlation receiver under these conditions is compared to that for additive white Gaussian noise (AWGN) channels. It is found that the approach performs poorly in the presence of impulsive noise. To overcome this problem, an impulse mitigation strategy derived from the myriad filtering framework is employed to produce reliable soft channel outputs over a wide range of noise characteristics. The asymptotic error probability performance of the chip-matched myriad filter (CMMyF)-based receivers is then computed and compared to the computer simulated expression. The results show that, in contrast to the linear filter, the CMMyF is effective in removing the impulsive noise and leads to a reliable recovery of the desired chips with low estimation error. The proposed method proves to be fruitful in that the subsequent k-opt multiuser detector is safe to process the chip samples obtained hereafter, thereby retaining all its optimality and advantages. (C) 2007 Elsevier B.V. All rights reserved

MAMI Tech Toolkit Utilising Action Research to Develop a Technological Toolkit to Facilitate Access to Music-Making

Music is essential to most of us, it can light up all areas of the brain, help develop skills with communication, help to establish identity, and allow a unique path for expression. However, barriers to access or gaps in provision can restrict access to music-making and sound exploration for some people. Research has shown that technology can provide unique tools to access music-making but that technology is underused by practitioners. This action research project details the development and design of a technological toolkit called MAMI – the Modular Accessible Musical Instrument technology toolkit - in conjunction with stakeholders from four research sites. Stakeholders included music therapists, teachers, community musicians, and children and young people. The overarching aims of the research were: to explore how technology was incorporated into practices of music creation and sound exploration; to explore the issues that stakeholders had with current music technology; to create novel musical tools and tools that match criteria as specified by stakeholders, and address issues as found in a literature review; to assess the effectiveness of these novel tools with a view to improving practices; and to navigate propagation of the practices, technologies, and methods used to allow for transferability into the wider ecology. Outcomes of the research include: a set of design considerations that contribute to knowledge around the design and practical use of technological tools for music-making in special educational needs settings; a series of methodological considerations to help future researchers and developers navigate the process of using action research to create new technological tools with stakeholders; and the MAMI Tech Toolkit – a suite of four bespoke hardware tools and accompanying software - as an embodiment of the themes that emerged from: the cycles of action research; the design considerations; and a philosophical understanding of music creation that foregrounds it as an situated activity within a social context

Bibliography of Lewis Research Center technical publications announced in 1989

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1989. All the publications were announced in the 1989 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

MAMI tech toolkit: utilising action research to develop a technological toolkit to facilitate access to music-making.

Music is essential to most of us, it can light up all areas of the brain, help develop skills with communication, help to establish identity, and allow a unique path for expression. However, barriers to access or gaps in provision can restrict access to music-making and sound exploration for some people. Research has shown that technology can provide unique tools to access music-making but that technology is underused by practitioners. This action research project details the development and design of a technological toolkit called MAMI – the Modular Accessible Musical Instrument technology toolkit - in conjunction with stakeholders from four research sites. Stakeholders included music therapists, teachers, community musicians, and children and young people. The overarching aims of the research were: to explore how technology was incorporated into practices of music creation and sound exploration; to explore the issues that stakeholders had with current music technology; to create novel musical tools and tools that match criteria as specified by stakeholders, and address issues as found in a literature review; to assess the effectiveness of these novel tools with a view to improving practices; and to navigate propagation of the practices, technologies, and methods used to allow for transferability into the wider ecology. Outcomes of the research include: a set of design considerations that contribute to knowledge around the design and practical use of technological tools for music-making in special educational needs settings; a series of methodological considerations to help future researchers and developers navigate the process of using action research to create new technological tools with stakeholders; and the MAMI Tech Toolkit – a suite of four bespoke hardware tools and accompanying software - as an embodiment of the themes that emerged from: the cycles of action research; the design considerations; and a philosophical understanding of music creation that foregrounds it as an situated activity within a social context