Tanlock based loop with improved performance

This thesis is focused on the design, analysis, simulation and implementation of new improved architectures of the Time Delay Digital Tanlock Loop (TDTL) based digital phase-locked loop (DPLL). The proposed architectures overcome some fundamental limitations exhibited by the original TDTL. These limitations include the presence of nonlinearity in the phase detector (PD), the non-zero phase error of the first-order loop, the restricted locking range, particularly of the second-order loop, the limited acquisition speed and the noise performance. Two approaches were adopted in this work to alleviate these limitations: the first involved modifying the original TDTL through the incorporation of auxiliary circuit blocks that enhance its performance, whilst the second involved designing new tanlock-based architectures. The proposed architectures, which resulted from the above approaches, were tested under various input signal conditions and their performance was compared with the original TDTL. The proposed architectures demonstrated an improvement of up to fourfold in terms of the acquisition times, twofold in noise performance and a marked enhancement in the linearity and in the locking range. The effectiveness of the proposed tanlock-based architectures was also assessed and demonstrated by using them in various applications, which included FM demodulation, FM threshold extension, FM demodulation with improved THD (total harmonic distortion), and Doppler effect improvement. The results from these applications showed that the performance of the new architectures outperformed the original TDTL. Real-time performance of these architectures was evaluated through implementation of some of them on an FPGA (field-programmable gate array) based system. Practical results from the prototype FPGA based implementations confirmed the simulation results obtained from MATLAB/Simulink

Software Defined Applications in Cellular and Optical Networks

abstract: Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. A novel access backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Based on software defined networking (SDN) a management mechanism that allows multiple operator to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells has been proposed. This dissertation also comprehensively survey the studies that examine the SDN paradigm in optical networks. Along with the PHY functional split improvements, the performance of Distributed Converged Cable Access Platform (DCCAP) in the cable architectures especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In the PHY functional split, in addition to the re-use of infrastructure with a common FFT module for multiple technologies, a novel cross functional split interaction to cache the repetitive QAM symbols across time at the remote node to reduce the transmission rate requirement of the fronthaul link has been proposed.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Survey of FPGA applications in the period 2000 – 2015 (Technical Report)

Romoth J, Porrmann M, Rückert U. Survey of FPGA applications in the period 2000 – 2015 (Technical Report).; 2017.Since their introduction, FPGAs can be seen in more and more different fields of applications. The key advantage is the combination of software-like flexibility with the performance otherwise common to hardware. Nevertheless, every application field introduces special requirements to the used computational architecture. This paper provides an overview of the different topics FPGAs have been used for in the last 15 years of research and why they have been chosen over other processing units like e.g. CPUs

A versatile data acquisition system for capturing electromagnetic emissions in VHF band

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research investigates the occurrence of EM emissions from compressed rock and assesses their value as precursors to earthquakes. It is understood that electromagnetic emissions are accompanied by crack generation in the Earth's crust, and effort has been targeted on the analysis of electromagnetic signals preceding seismic events. There is a need for a robust Data Acquisition System for the reliable collection of such signals. The design and deployment of a novel system form part of this research. The EM data collected by the Data Acquisition System is subsequently analysed and correlations are made with natural phenomena. The design of the Data Acquisition System is presented and meets a specification which includes accuracy, robustness, power consumption, remote configurability achieved by the development of a novel architecture for flash memories which significantly increases the live span of these devices. The measuring of electromagnetic emissions should be performed by reliable systems, using devices that fully correspond to the specifications set by the needs of this research. This type of systems is not fully covered by existing commercial devices. These prototype VHF field stations (ground base - electromagnetic variation monitors in VHF band) are located around the Hellenic Are. This region is one of the most seismically active regions in western Eurasia due to subduction of the oceanic African lithosphere beneath the Eurasian plate. After approximately two years of electromagnetic VHF data collection, the final stage of this project took place. In this stage, possible correlation between naturally occurring electromagnetic emissions in VHF band and seismic events within a predefined radius around the observation location is investigated. Supplementary, effects of alternative electromagnetic sources, such as solar activity, is considered. Whilst EM emissions from compressed rocks can be demonstrated in the laboratory, it was found from a two-year evaluation that no reliable correlation with earthquake events could be established. However, significant patterns of activity were detected in EM spectrum and it was shown that these correlate strongly with other naturally occurring phenomena such as solar flares. The Data Acquisition System as developed in this thesis has related applications in long term and remote sensing operations including meteorology, environmental analysis and surveillance.Funding was obtained from the National Foundation of Scholarships (I. K. Y.), and co-funded by the European Social Fund and National Resources - (EPEAEK II) ARXIMIDIS

A versatile data acquisition system for capturing electromagnetic emissions in VHF band

This research investigates the occurrence of EM emissions from compressed rock and assesses their value as precursors to earthquakes. It is understood that electromagnetic emissions are accompanied by crack generation in the Earth's crust, and effort has been targeted on the analysis of electromagnetic signals preceding seismic events. There is a need for a robust Data Acquisition System for the reliable collection of such signals. The design and deployment of a novel system form part of this research. The EM data collected by the Data Acquisition System is subsequently analysed and correlations are made with natural phenomena. The design of the Data Acquisition System is presented and meets a specification which includes accuracy, robustness, power consumption, remote configurability achieved by the development of a novel architecture for flash memories which significantly increases the live span of these devices. The measuring of electromagnetic emissions should be performed by reliable systems, using devices that fully correspond to the specifications set by the needs of this research. This type of systems is not fully covered by existing commercial devices. These prototype VHF field stations (ground base - electromagnetic variation monitors in VHF band) are located around the Hellenic Are. This region is one of the most seismically active regions in western Eurasia due to subduction of the oceanic African lithosphere beneath the Eurasian plate. After approximately two years of electromagnetic VHF data collection, the final stage of this project took place. In this stage, possible correlation between naturally occurring electromagnetic emissions in VHF band and seismic events within a predefined radius around the observation location is investigated. Supplementary, effects of alternative electromagnetic sources, such as solar activity, is considered. Whilst EM emissions from compressed rocks can be demonstrated in the laboratory, it was found from a two-year evaluation that no reliable correlation with earthquake events could be established. However, significant patterns of activity were detected in EM spectrum and it was shown that these correlate strongly with other naturally occurring phenomena such as solar flares. The Data Acquisition System as developed in this thesis has related applications in long term and remote sensing operations including meteorology, environmental analysis and surveillance.EThOS - Electronic Theses Online ServiceNational Foundation of Scholarships (I.K.Y.)European Social Fund and National Resources - (EPEAEK II) ARXIMIDISGBUnited Kingdo

A versatile data acquisition system for capturing electromagnetic emissions in VHF band

This research investigates the occurrence of EM emissions from compressed rock and assesses their value as precursors to earthquakes. It is understood that electromagnetic emissions are accompanied by crack generation in the Earth's crust, and effort has been targeted on the analysis of electromagnetic signals preceding seismic events. There is a need for a robust Data Acquisition System for the reliable collection of such signals. The design and deployment of a novel system form part of this research. The EM data collected by the Data Acquisition System is subsequently analysed and correlations are made with natural phenomena. The design of the Data Acquisition System is presented and meets a specification which includes accuracy, robustness, power consumption, remote configurability achieved by the development of a novel architecture for flash memories which significantly increases the live span of these devices. The measuring of electromagnetic emissions should be performed by reliable systems, using devices that fully correspond to the specifications set by the needs of this research. This type of systems is not fully covered by existing commercial devices. These prototype VHF field stations (ground base - electromagnetic variation monitors in VHF band) are located around the Hellenic Are. This region is one of the most seismically active regions in western Eurasia due to subduction of the oceanic African lithosphere beneath the Eurasian plate. After approximately two years of electromagnetic VHF data collection, the final stage of this project took place. In this stage, possible correlation between naturally occurring electromagnetic emissions in VHF band and seismic events within a predefined radius around the observation location is investigated. Supplementary, effects of alternative electromagnetic sources, such as solar activity, is considered. Whilst EM emissions from compressed rocks can be demonstrated in the laboratory, it was found from a two-year evaluation that no reliable correlation with earthquake events could be established. However, significant patterns of activity were detected in EM spectrum and it was shown that these correlate strongly with other naturally occurring phenomena such as solar flares. The Data Acquisition System as developed in this thesis has related applications in long term and remote sensing operations including meteorology, environmental analysis and surveillance.EThOS - Electronic Theses Online ServiceNational Foundation of Scholarships (I.K.Y.)European Social Fund and National Resources - (EPEAEK II) ARXIMIDISGBUnited Kingdo

Princeton Advanced Satellite Study Final Report, 8 Mar. 1965 - 15 May 1966

Development of large aperture spaceborne telescope and high resolution ultraviolet photometry for orbiting astronomical satellit

Ethnobotanicals for management of the brown ear tick Rhipicephalus appendiculatus in western Kenya

This thesis describes the results of a study to assess the effect of ethnobotanical products on the behaviour of the brown ear tick Rhipicephalus appendiculatus, the main vector of East Coast fever in sub-Saharan Africa. Ethnoknowledge of the Bukusu people in western Kenya on tick control and management was evaluated to identify plants that affect livestock ticks, using participatory action research approaches. More than 150 plant species spread over 110 genera and 51 families were identified and documented. From these, eight plants were selected and their essential oils extracted and used for screening in the laboratory on their behavioural effects on ticks. From these, the plants Tagetes minuta and Tithonia diversifolia were chosen for further studies. The essential oils of these two plants were further extracted and used in laboratory and field bioassays. From the laboratory assay, using a dual-choice apparatus, it was found that essential oils of both T. minuta and T. diversifolia affect tick climbing behaviour, representing a repellent response. Dose response effects were observed. On steers, differential effects to the essential oils were observed with R. appendiculatus, which prefer to feed mainly inside the ears of the host animal. It was found that treatment of the ear region with the essential oils of both T. minuta and T. diversifolia significantly deterred ticks from reaching the ear. The essential oils of T. minuta and T. diversifolia were evaluated in the field and significantly shown to affect R. appendiculatus and other ticks naturally attached to the host animals. The essential oil of T. minuta affects R. appendiculatus and other ticks more than the essential oil of T. diversifolia. The results suggest the potential for essential oils to be incorporated in the on-host “push” and “push-pull” strategy for the control and management of R. appendiculatus, other affected livestock ticks and associated tick-borne diseases among the resource-limited livestock farming community in tropical Africa. <br/