Systems and Communications Commons^™

Maine’S Three Ring Binder, Fletcher Kittredge

Maine Policy Review

Although Maine is a rural state, it has had success in keeping pace with technological changes since the rise of the Internet 20 years ago. In this section, authors describe some of these successes and the challenges faced by both consumers and libraries in the new digital environment. Fletcher Kittredge presents the history and promise of Maine’s “Three Ring Binder,” a new and important fiber optic network that will bring high-speed broadband connectivity to rural parts of the state. The Three Ring Binder is expected both to improve economic opportunities for businesses and to increase high-speed Internet access for ...

Omnidirectional Circularly Polarized Patch Antenna With Post Manufacture Characteristic Refinement, Adam Narbudowicz, Xiulong Bao, Max Ammann

Conference Papers

We propose an omnidirectional circularly polarised planar microstrip patch antenna, in which both impedance bandwidth and circular polarization properties can be adjusted after antenna manufacture. This is done by appropriately tuning four adjustable capacitors, incorporated into the patches. To demonstrate the properties, the proposed antenna is tuned to the GPS L1 band and then re-tuned for Beidou/Galileo E2 band by only changing capacitors values. Design guidelines for such retuning are provided.

Detecting Point-Like Sources Of Unknown Frequency Spectra, Raffaele Solimene, Giuseppe Ruvio, Angela Dell’Aversano, Antonio Cuccaro, Max Ammann, Rocco Pierri

Articles

The problem of detecting point-like sources whose frequency spectrum is unknown is addressed. Limitations of single-frequency approaches are identified by analytical as well as numerical arguments. To overcome these limits, different multifrequency approaches which combine frequency data incoherently are compared. In particular, a novel multifrequency MUSIC-like algorithm based on interferometric concepts is proposed. Results show that the algorithm outperforms other methods under comparison.

A Compact Shorted Printed Monopole Antenna For Tv White Space Trials, Matthias John, Max Ammann

Conference Papers

This paper presents a compact shorted printed monopole antenna for machine-to-machine, remote sensing and rural wireless applications in the TV whitespace band from 470 MHz to 862 MHz. The antennas performance in this operating band is demonstrated.

Radio Frequency Direction Of Arrival Determination, Daniel A. Lazar

Undergraduate Research Symposium

This project is focused on implementing source location algorithms to find the direction of arrival of transmitted radio frequency signals on an array of receivers. The MuSIC (multiple signal classification) algorithm is used, as well as a variant, smooth-MuSIC, which mitigates the effects of multipath interference. Beamforming techniques, which combine temporal and spatial filtering, are also used to find the direction of arrival. These strategies minimize the transmission power needed to send a signal. Further work building on this research can implement directional transmission and receiving with beamforming, which yields many advantages including minimized signal interception. The results from this ...

Detection, Receivers, And Performance Of Cpfsk And Cpck, Mohammed Zourob

University of Western Ontario - Electronic Thesis and Dissertation Repository

Continuous Phase Modulation (CPM) is a power/bandwidth efficient signaling technique for data transmission. In this thesis, two subclasses of this modulation called Continuous Phase Frequency Shift Keying (CPFSK) and Continuous Phase Chirp Keying (CPCK) are considered and their descriptions and properties are discussed in detail and several illustrations are given. Bayesian Maximum Likelihood Ratio Test (MLRT) is designed for detection of CPFSK and CPCK in AWGN channel. Based on this test, an optimum receiver structure, that minimizes the total probability of error, is obtained. Using high- and low-SNR approximations in the Bayesian test, two receivers, whose performances are ...

Optimization And Learning In Energy Efficient Cognitive Radio System, Kun Zheng

Doctoral Dissertations

Energy efficiency and spectrum efficiency are two biggest concerns for wireless communication. The constrained power supply is always a bottleneck to the modern mobility communication system. Meanwhile, spectrum resource is extremely limited but seriously underutilized.

Cognitive radio (CR) as a promising approach could alleviate the spectrum underutilization and increase the quality of service. In contrast to traditional wireless communication systems, a distinguishing feature of cognitive radio systems is that the cognitive radios, which are typically equipped with powerful computation machinery, are capable of sensing the spectrum environment and making intelligent decisions. Moreover, the cognitive radio systems differ from traditional wireless ...

Techniques For Wireless Channel Modeling In Harsh Environments, Phani Teja Kuruganti

Doctoral Dissertations

With the rapid growth in the networked environments for different industrial, scientific and defense applications, there is a vital need to assure the user or application a certain level of Quality of Service (QoS). Environments like the industrial environment are particularly harsh with interference from metal structures (as found in the manufacturing sector), interference generated during wireless propagation, and multipath fading of the radio frequency (RF) signal all invite novel mitigation techniques. The challenge of achieving the benefits like improved energy efficiency using wireless is closely coupled with maintaining network QoS requirements. Assessment and management of QoS needs to occur ...

Analysis Of The Feasibility Of Utilizing Wakeup Radios To Optimize Energy And Latency Performance Of Wireless Sensor Networks, Benjamin D. Parks

Dissertations & Student Research in Computer Electronics & Engineering

Wireless sensor networks (WSNs) have the potential to radically improve our lives by pervasive environmental monitoring in many applications. However, there are many applications that would be ideal for WSNs, but where reportable events occur with long (days, weeks) or unpredictable durations between occurrences. These uses are hampered by the high energy and latency costs of always-on and periodic wakeup networks, which waste energy on node synchronization and idle monitoring of the RF channel, and exhibit unacceptably high latency for urgent events, e.g., alarms. This thesis proposes, designs, assembles and tests, in a multi-hop WSN test bed, a wakeup ...

Architecture-Independent Dynamic Information Flow Tracking, Ryan James Whelan

Electrical and Computer Engineering Master's Theses

Dynamic information flow tracking is a well-known dynamic software analysis technique with a wide variety of applications that range from making systems more secure, to helping developers and analysts better understand the code that systems are executing. Traditionally, the fine-grained analysis capabilities that are desired for the class of these systems which operate at the binary level require that these analyses are tightly coupled to a specific ISA. This fact places a heavy burden on developers of these systems since significant domain knowledge is required to support each ISA, and our ability to amortize the effort expended on one ISA ...

Planar Tunable Rf/Microwave Devices With Magnetic, Ferroelectric And Multiferroic Materials, Jing Wu

Electrical Engineering Dissertations

Modern ultra wideband communication systems and radars, and metrology systems all need reconfigurable subsystems that are compact, lightweight, and power efficient. At the same time, isolators with a large bandwidth are widely used in communication systems for enhancing the isolation between the sensitive receiver and power transmitter. Conventional Isolators based on the non-reciprocal ferromagnetic resonance (FMR) of microwave ferrites in waveguide. However, these approaches are usually bulky. This dissertation focuses on theoretical study, numerical evaluation and measurement verification of novel planar RF/microwave devices with magnetic substrates and superstrates, demonstrating tunable and non-reciprocal characteristics, so that size, weight and cost ...

Design And Implementation Of Patient Specific Virtual Reality Systems For Motor Rehabilitation, Mark Langdon Sivak

Computer Engineering Dissertations

There is a need for low-cost, in-home rehabilitation systems with increasing numbers of strokes per year. Therefore a virtual reality system for home use in rehabilitation of the hand and wrist that included hardware, middleware, and software was created and tested with healthy subjects. The Angle Tracking and Location At-home System (ATLAS) was created with potentiome-ter bend sensors to track finger angle and inertial measurement units (IMUs) to track hand orientation and position. To facilitate the communication between the ATLAS and a computer the Device Agnostic Virtual Environment (DAVE) was created as the middleware solution. Patient specific virtual environments have ...

Circuit Design For Energy Harvesting From Digital Tv Band, David Richard Lewis

Electrical and Computer Engineering Master's Theses

Radio Frequency (RF) energy harvesting is relatively unexplored research area, owing to the challenges involved in converting efficiently the low energy density of RF energy in the ambient environment to useful electrical power. The proposed research is aimed at making a case for self-sustaining RF energy harvesting sensors powered by the continuous radiation emitted from external television (TV) stations as part of their scheduled program broadcasts. This thesis explores the prototype design and investigates the limitations of creating such a self-powered network using RF energy harvesting circuits operating around 600 MHz in the VHF digital television broadcast frequency band. A ...

Bit Error Rate Estimation In Wimax Communications At Vehicular Speeds Using Nakagami-M Fading Model, Biswojit Bose

Theses: Doctorates and Masters

The wireless communication industry has experienced a rapid technological evolution from its basic first generation (1G) wireless systems to the latest fourth generation (4G) wireless broadband systems. Wireless broadband systems are becoming increasingly popular with consumers and the technological strength of 4G has played a major role behind the success of wireless broadband systems. The IEEE 802.16m standard of the Worldwide Interoperability for Microwave Access (WiMAX) has been accepted as a 4G standard by the Institute of Electrical and Electronics Engineers in 2011. The IEEE 802.16m is fully optimised for wireless communications in fixed environments and can deliver ...

Learning At The Virtualization Layer: Intrusion Detection And Workload Characterization From Within The Virtual Machine Monitor, Fatemeh Azmandian

Electrical Engineering Dissertations

Virtualization technology has many attractive qualities including improved reliability, scalability, and resource sharing/management. As a result, virtualization has been deployed on an array of platforms, from mobile devices to high-end enterprise servers. In this work, we contribute to the benefits of virtualization by providing two key features for virtual machines (VMs): enhanced security using a novel intrusion detection system and workload characterization for virtual machine workloads. What makes our contributions unique is the fact that we only make use of low-level architectural data available at the virtual machine monitor (VMM) layer. This gives rise to several advantages, including a ...

Fast Sparse Subspace Identification Tools With Applications To Dynamic Vision, Mustafa Ayazoglu

Electrical Engineering Dissertations

Dynamic vision, a sub-area of computer vision, focuses on the problems where some sort of gradual evolution of some variables in time (or space) exists. So the evolution of the variables contains important information. However the utilization of this extra information in the variable evolution brings added complexity and it is mathematically hard to exploit without specially tailored tools. Hence usually the existing methods for dynamic vision, either discard the dynamics information or use it in a limited manner. However when used wisely it helps to solve the problems and increases the robustness of the methods.

Motivated by these facts ...

Proximity Study Of A Uwb Directional Conformal Antenna On Water Pipe, Domenico Gaetano, Max Ammann, Patrick Mcevoy, Matthias John, Louise Keating, Frances Horgan

Articles

A preliminary study on the conformal properties of an antipodal exponentially tapered antenna placed on the surface of a flow meter system in the UWB range is presented. It was observed that the water effect can be mitigated by shifting the antenna away from the pipe surface.

Dual-Band Omnidirectional Circularly Polarized Antenna, Adam Narbudowicz, Xiulong Bao, Max Ammann

Articles

A dual-band omnidirectional circularly polarized antenna is proposed. The antenna comprises back-to-back microstrip patches fed by a coplanar waveguide. A very low frequency ratio of 1.182 has been achieved, which can be easily tuned by adjusting four lumped capacitors incorporated into the antenna. An analysis of the omnidirectional circular polarization mechanism as well the dual band operation is provided and confirmed by numerical and experimental data. Key parameters to tune the resonant frequencies and the axial ratio have been identified. The prototype antenna provides omnidirectional circular polarization in one plane with cross polar isolation better than 12 dB for ...

Integration Of Inverted-F Antenna With Solar Cell Substitute, Oisin O’Conchubhair, Patrick Mcevoy, Max Ammann, Giuseppe Ruvio

Conference Papers

A study into the effect of a solar cell lattice on the performance of an Inverted-F antenna is presented. An FR-4 substrate with a lattice of copper electrodes printed on one side and a solid copper ground plane on the other is used to represent a polycrystalline solar cell. The effect of the lattice orientation on the performance of the Inverted-F antenna is discussed.

Circularly Polarized Terminal Antennas For Emerging Wireless Systems, Max Ammann, Xiulong Bao, Adam Narbudowicz

Conference Papers

Several types of omni-directional Circularly Polarized (CP) antennas are presented, which are employed by three different types of feedlines: Coplanar Waveguide (CPW) fed, Microstrip fed, and Differential-fed, to achieve omni-directional CP performances. The Dual-frequency Omni-directional CP antenna is proposed by using slot and inductor embedded into radiated patches. These omnidirectional CP antennas have potential application on GPS, WLAN and RFID systems.