41 research outputs found

    Ultra Wideband

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    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

    Implementation of Offset Pulse Position Modulation

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    Optical fibre systems have played a key role in making possible the extraordinary growth in world-wide communications that has occurred in the last 25 years, and are vital in enabling the proliferating use of the Internet. Its high bandwidth capabilities, low attenuation characteristics, low cost, and immunity from the many disturbances that can afflict electrical wires and wireless communication links make it ideal for gigabit transmission and a major building block in the telecommunication infrastructure. The main concern of this thesis is a full and detailed investigation and implementation of the Offset Pulse Position Modulation (Offset PPM) communication system. Novel work is carried out for applying Offset PPM over an optical communication channel theoretically and experimentally to examine the system performance. An Offset PPM encoder and decoder were implemented to code Pulse Code Modulation (PCM) format into Offset PPM format and to decode back the Offset PPM to PCM. The first paradigm of implementation was implemented using electronic components. A further investigation took place on the Offset PPM associated output. Computer programming and simulation using the VHSIC Hardware Description Language (VHDL) of this PPM code was considered and comparison with previous theoretical results presented. The received Offset PPM signal returned back to its original input PCM form without errors. Successful VHDL and Field Programmable Gate Array (FPGA) implementation using Altera Quartus II of Offset PPM encoder and decoder as a single system has been presented in the study. An FPGA embedded Bit Error Rate (BER) test device has also been implemented for sensitivity measurements purposes and all the designs have been tested successfully with back-to-back testing. Results show that Offset PPM is an advantageous PPM code for optic communication. Furthermore, the system has achieved a very high data rate of 50 Mb/s without an optical communication set. An optical communication system (transmitter/receiver) over POF was developed and the Offset PPM scheme was investigated through this optical channel. Results show that the Offset PPM sequence transferred through the optic system without being altered. In addition, this implementation is optimised PPM coding; the system is working perfectly with up to 10 Mb/s with 10-12 BER based on the limitations of the optical communication set. All the results and analyses indicate that Offset PPM is an ideal alternative to be considered for highly dispersive optical channels, and performance evaluation for higher bandwidths also favourably compares to existing coding schemes

    Development and Experimental Analysis of Wireless High Accuracy Ultra-Wideband Localization Systems for Indoor Medical Applications

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    This dissertation addresses several interesting and relevant problems in the field of wireless technologies applied to medical applications and specifically problems related to ultra-wideband high accuracy localization for use in the operating room. This research is cross disciplinary in nature and fundamentally builds upon microwave engineering, software engineering, systems engineering, and biomedical engineering. A good portion of this work has been published in peer reviewed microwave engineering and biomedical engineering conferences and journals. Wireless technologies in medicine are discussed with focus on ultra-wideband positioning in orthopedic surgical navigation. Characterization of the operating room as a medium for ultra-wideband signal transmission helps define system design requirements. A discussion of the first generation positioning system provides a context for understanding the overall system architecture of the second generation ultra-wideband positioning system outlined in this dissertation. A system-level simulation framework provides a method for rapid prototyping of ultra-wideband positioning systems which takes into account all facets of the system (analog, digital, channel, experimental setup). This provides a robust framework for optimizing overall system design in realistic propagation environments. A practical approach is taken to outline the development of the second generation ultra-wideband positioning system which includes an integrated tag design and real-time dynamic tracking of multiple tags. The tag and receiver designs are outlined as well as receiver-side digital signal processing, system-level design support for multi-tag tracking, and potential error sources observed in dynamic experiments including phase center error, clock jitter and drift, and geometric position dilution of precision. An experimental analysis of the multi-tag positioning system provides insight into overall system performance including the main sources of error. A five base station experiment shows the potential of redundant base stations in improving overall dynamic accuracy. Finally, the system performance in low signal-to-noise ratio and non-line-of-sight environments is analyzed by focusing on receiver-side digitally-implemented ranging algorithms including leading-edge detection and peak detection. These technologies are aimed at use in next-generation medical systems with many applications including surgical navigation, wireless telemetry, medical asset tracking, and in vivo wireless sensors

    A review of gallium nitride LEDs for multi-gigabit-per-second visible light data communications

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    The field of visible light communications (VLC) has gained significant interest over the last decade, in both fibre and free-space embodiments. In fibre systems, the availability of low cost plastic optical fibre (POF) that is compatible with visible data communications has been a key enabler. In free-space applications, the availability of hundreds of THz of the unregulated spectrum makes VLC attractive for wireless communications. This paper provides an overview of the recent developments in VLC systems based on gallium nitride (GaN) light-emitting diodes (LEDs), covering aspects from sources to systems. The state-of-the-art technology enabling bandwidth of GaN LEDs in the range of >400 MHz is explored. Furthermore, advances in key technologies, including advanced modulation, equalisation, and multiplexing that have enabled free-space VLC data rates beyond 10 Gb/s are also outlined

    Technical design of the phase I Mu3e experiment

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    The Mu3e experiment aims to find or exclude the lepton flavour violating decay at branching fractions above . A first phase of the experiment using an existing beamline at the Paul Scherrer Institute (PSI) is designed to reach a single event sensitivity of . We present an overview of all aspects of the technical design and expected performance of the phase I Mu3e detector. The high rate of up to muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra thin tracking detector based on high-voltage monolithic active pixel sensors combined with scintillating fibres and tiles for precise timing measurements

    Technical design of the phase I Mu3e experiment

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    The Mu3e experiment aims to find or exclude the lepton flavour violating decay μ→eee\mu \rightarrow eee at branching fractions above 10−1610^{-16}. A first phase of the experiment using an existing beamline at the Paul Scherrer Institute (PSI) is designed to reach a single event sensitivity of 2⋅10−152\cdot 10^{-15}. We present an overview of all aspects of the technical design and expected performance of the phase~I Mu3e detector. The high rate of up to 10810^{8} muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra thin tracking detector based on high-voltage monolithic active pixel sensors combined with scintillating fibres and tiles for precise timing measurements.Comment: 114 pages, 185 figures. Submitted to Nuclear Instruments and Methods A. Edited by Frank Meier Aeschbacher This version has many enhancements for better readability and more detail
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