Systems and Communications Commons^™

Path Loss In An Urban Peer-To-Peer Channel For Six Public-Safety Frequency Bands, David W. Matolak, Qian Zhang, Qiong Wu

Faculty Publications

We provide path loss data and models for a peer-to-peer wireless channel for an urban environment in six public safety bands, for simultaneous transmission to five spatially separated receiving sites. Results are from measurements in Denver, Colorado. The six frequencies at which we measured are (in MHz) 430, 750, 905, 1834, 2400, and 4860. Both line-of-sight and non-line-of-sight conditions were covered, and we quantify path loss exponents and linear-fit standard deviations as functions of frequency and location. Line-of-sight results agree with prior work, but non-line-of-sight exponents, from 3.6-7.3, are generally larger than in most other references.

Buddy: A Breathalyzer For Iphone, Douglas Blaalid, Brandon Bevans

Electrical Engineering

Buddy is a Breathalyzer for the iPhone designed to be more a product than a project. Through proprietary hardware and a custom iOS application, Buddy provides users with a previously untapped link from the alcohol in their body to the display on their phones. Buddy uses an alcohol sensor connected to an Arduino Uno to accurately detect the BAC of the user’s breath. The BAC is then transmitted to an iPhone via the headphone jack where it is displayed and logged in a captivating app. The finished prototype successfully measured the approximate BAC of intoxicated users. The product website has …

High Frequency Open Air Optical Communication System, Alexander C. Wolff

Electrical Engineering

The goal of this project is to create a wireless optical communication system that operates at high frequencies (up to 3 GHz). The system will function by taking a digital electric input signal, converting it to a photonic signal, recovering the signal at the other end of a short distance (~1 foot) and converting it back into a digital signal. Unlike the more common fiber-optic data transmission systems, this system will transmit light through air, instead of fiber, as its medium. Doing so will have the benefits of a wireless system combined with the benefits from an optical system, including …

A Novel Unit Cell Antenna For Highly Integrated Phased Arrays In The Shf Band, Timothy Bryan Ogilvie

Master's Theses

Phased arrays are electromagnetic antenna systems comprised of many radiating elements and processing electronics. Radiating elements are typically positioned in an orderly grid within the antenna aperture. In the receive mode of operation, radiating elements capture some of the signal energy from incoming radiation and guide these signals to processing electronics. Signals are filtered and amplified to maintain the desired sensitivity and complexly weighted using circuits with reconfigurable amplification gain and phase delay. Finally, all signals are combined. The summation of these complexly weighted spatial samples forms a spatial filter in the same way complexly weighted temporal samples establish a …

Nonlinearity Analysis And Predistortion Of 4g Wireless Communication Systems, Xiao Li

Dissertations and Theses

The nonlinearity of RF power amplifiers (PA) is one of critical concerns for RF designers because it causes spectral regrowth related to in-band and out-of-band spurious emissions control in communication standards. Traditionally, RF power amplifiers must be backed off considerably from the peak of their power level in order to prevent spectral regrowth. The digital predistortion (DPD) technique is being widely used for compensation of the nonlinearity of RF power amplifiers, as the high power efficiency becomes increasely important in wireless communication systems.

However, the latest generations of communication systems, such as Wi-Fi, WiMAX, and LTE, using wider bandwidth have …

Reliability Analysis Of Social Networks, Kellie R. Schneider

Graduate Theses and Dissertations

The primary focus of this dissertation is on the quantification of actor interaction and the dissemination of information through Social networks. Social networks have long been used to model the interactions between people in various Social and professional contexts. These networks allow for the explicit modeling of the complex interrelations between relevant individuals within an organization and the role they play in the decision making process. This dissertation considers Social networks represented as network flow models in which actors have the ability to provide some level of influence over other actors within the network. The models developed incorporate performance metrics …

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.

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

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

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 receiver …

Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald

Electrical & Computer Engineering Theses & Dissertations

Increasing numbers of wireless devices and mobile data requirements have led to a spectrum shortage. However spectrum utilization percentages are often low due to the current static spectrum allocation process where primary users (PUs) are given exclusive use to spectrum. Several mechanisms to increase spectrum utilization have been proposed including opportunistic spectrum access (OSA). Cognitive Radio (CR) is an emerging concept in wireless communication systems that aims to enable OSA in licensed frequencies by secondary users (SUs). CR systems are expected to sense the spectrum in order to determine if the PU is transmitting. Therefore OSA performance relies on the …

Communication Technology In The Military, Jordan Diehl

Senior Seminars

No abstract 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.

Time Synchronization For Ofdm Transmission With Applications To 4g Wimax Wireless Systems, Hamad Alhajri

Electrical & Computer Engineering Theses & Dissertations

Orthogonal Frequency Division Multiplexing (OFDM) has recently gained a lot of attention as a promising new technology for Broadband Wireless Access. OFDM-based communication systems decompose a high rate data stream into a set of lower data rate streams that are transmitted simultaneously over multiple subcarriers. WiMAX is an efficient and reliable wireless transmission standard that employs OFDM transmission. Due to its flexibility and mobility, WiMAX is becoming a preferred air interface for next generation broadband wireless systems. OFDM systems, including WiMAX, are very sensitive to time offsets introduced by radio signal propagation between transmitters and receivers. The lack of time …

Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh

College of Computing and Digital Media Dissertations

Voice over IP (VoIP) systems are gaining increased popularity due to the cost effectiveness, ease of management, and enhanced features and capabilities. Both enterprises and carriers are deploying VoIP systems to replace their TDM-based legacy voice networks. However, the lack of engineering models for VoIP systems has been realized by many researchers, especially for large-scale networks. The purpose of traffic engineering is to minimize call blocking probability and maximize resource utilization. The current traffic engineering models are inherited from the legacy PSTN world, and these models fall short from capturing the characteristics of new traffic patterns. The objective of this …

Automatic Modulation Classification Of Common Communication And Pulse Compression Radar Waveforms Using Cyclic Features, John A . Hadjis

Theses and Dissertations

This research develops a feature-based MAP classification system and applies it to classify several common pulse compression radar and communication modulations. All signal parameters are treated as unknown to the classifier system except SNR and the signal carrier frequency. The features are derived from estimated duty cycle, cyclic spectral correlation, and cyclic cumulants. The modulations considered in this research are BPSK, QPSK, 16-QAM, 64-QAM, 8-PSK, and 16-PSK communication modulations, as well as Barker coded, Barker coded, Barker coded, Frank coded, Px49 coded, and LFM pulse compression modulations. Simulations show that average correct signal modulation type classification %C 90% is achieved …

Spectrum Regrowth For Ofdm-Based Lte And Wimax Systems, Bosi Chen

Dissertations and Theses

An abstract of the thesis of Bosi Chen for the Master of Science in Electrical and Computer Engineering presented Aug 1st, 2012. Title: Spectrum Regrowth for OFDM-based LTE and WiMAX Systems. In OFDM-based (Orthogonal Frequency Dimension Multiplexing) LTE (Long Term Evolution) and WiMAX (Worldwide Interoperability for Microwave Access) Systems, one of the critical components is the RF power amplifier. With current technologies, RF power amplifiers are not perfectly linear. The nonlinearity of an RF power amplifier is one of the main concerns in RF power amplifier design. The nonlinearity control is described by the out-of-band power emission levels, and the …

Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer, William K. Lewis, C. G. Rumchik, M. J. Smith, K. A. Shiral Fernando, Christopher A. Crouse, Jonathan E. Spowart, Elena A. Guliants, Christopher E. Bunker

Electrical and Computer Engineering Faculty Publications

Aluminum nanoparticles and explosive formulations that incorporate them have been a subject of ongoing interest due to the potential of aluminum particles to dramatically increase energy content relative to conventional organic explosives. We have used time-resolved atomic and molecular emission spectroscopy to monitor the combustion of aluminum nanoparticles within the overall chemical dynamicsof post-detonation fireballs. We have studied the energy release dynamics of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) charges incorporating three types of aluminum nanoparticles: commercial oxide-passivated nanoparticles, oleic acid-capped aluminum nanoparticles (AlOA), and nanoparticles in which the oxide shell of the particle has been functionalized with an acrylic monomer and copolymerized into …

Maintaining The Master International Frequency Register, Frans G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

The present paper is the written elaboration of a presentation held under the same title at the workshop “International Regulations of Space Communications” held in Luxembourg on 24 and 25 May 2012. Consequently, the topic of this paper, the maintenance of the Master International Frequency Register as a key tool for allowing satellite communications to be a viable international sector of space activities, is viewed through the looking glass of the session title, “WRC-12 from the Perspective of International Telecommunications Law.”

In other words, it does not purport to deal with the actual details of maintaining the Register …

A New Variable Step-Size Zero-Point Attracting Projection Algorithm, Jianming Liu, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new variable step-size (VSS) scheme for the recently introduced zero-point attracting projection (ZAP) algorithm. The proposed variable step-size ZAPs are based on the gradient of the estimated filter coefficients' sparseness that is approximated by the difference between the sparseness measure of current filter coefficients and an averaged sparseness measure. Simulation results demonstrate that the proposed approach provides both faster convergence rate and better tracking ability than previous ones. © 2013 IEEE.

Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao

Theses and Dissertations--Electrical and Computer Engineering

In immersive audio environments with distributed microphones, Independent Component Analysis (ICA) can be applied to uncover signals from a mixture of other signals and noise, such as in a cocktail party recording. ICA algorithms have been developed for instantaneous source mixtures and convolutional source mixtures. While ICA for instantaneous mixtures works when no delays exist between the signals in each mixture, distributed microphone recordings typically result various delays of the signals over the recorded channels. The convolutive ICA algorithm should account for delays; however, it requires many parameters to be set and often has stability issues. This thesis introduces the …

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 both …

Tunable Fano Resonances Based On Two-Beam Interference In Microring Resonator, Ting Hu, Ping Yu, Chen Qui, Huiye Qui, Fan Wang, Mei Yang, Xiaoqing Jiang, Hui Yu, Jianyi Yang

Electrical & Computer Engineering Faculty Research

In this paper, a resonant system is demonstrated on silicon-on-insulator wafer to achieve tunable Fano resonances. In this system, the Fano resonance originates from the interference of two beams resonant in the microring resonator. The shapes of the Fano resonances are tunable through controlling the phase difference of the two beams. Both large slope and high extinctionratio (ER) are obtained when the phase difference is 0.5π or 1.5π. Experimental results show that Fano resonances with steep slope and ER over 20 dB are achieved in the whole free spectral range by controlling the microheaters to meet the phase condition.

Estimation Of Performance Indices For The Planning Of Sustainable Transportation Systems, Alexander Paz, Pankaj Maheshwari

Electrical & Computer Engineering Faculty Research

In the context of sustainable transportation systems, previous studies have either focused only on the transportation systemor have not used a methodology that enables the treatment of incomplete, vague, and qualitative information associated with the available data. This study proposes a system of systems (SOS) and a fuzzy logic modeling approach. The SOS includes the Transportation, Activity, and Environment systems. The fuzzy logic modeling approach enables the treatment of the vagueness associated with some of the relevant data. Performance Indices (PIs) are computed for each system using a number of performance measures. The PIs illustrate the aggregated performance of each …

Optimal Network Topologies And Resource Mappings For Heterogeneous Networks-On-Chip, Haera Chung

Dissertations and Theses

Communication has become a bottleneck for modern microprocessors and multi-core chips because metal wires don't scale. The problem becomes worse as the number of components increases and chips become bigger. Traditional Systems-on-Chips (SoCs) interconnect architectures are based on shared-bus communication, which can carry only one communication transaction at a time. This limits the communication bandwidth and scalability. Networks-on-Chip (NoC) were proposed as a promising solution for designing large and complex SoCs. The NoC paradigm provides better scalability and reusability for future SoCs, however, long-distance multi-hop communication through traditional metal wires suffers from both high latency and power consumption. A radical …

Performance Evaluation And Comparison Of Distributed Messaging Using Message Oriented Middleware, Naveen Mupparaju

UNF Graduate Theses and Dissertations

Message Oriented Middleware (MOM) is an enabling technology for modern event- driven applications that are typically based on publish/subscribe communication [Eugster03]. Enterprises typically contain hundreds of applications operating in environments with diverse databases and operating systems. Integration of these applications is required to coordinate the business process. Unfortunately, this is no easy task. Enterprise Integration, according to Brosey et al. (2001), "aims to connect and combines people, processes, systems, and technologies to ensure that the right people and the right processes have the right information and the right resources at the right time"[Brosey01]. Communication between different applications can be achieved …

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 very high …