Systems and Communications Commons^™

Automated Basketball Return System, Victor Mendoza, Chris Chamberlain

Electrical Engineering

The project is meant to assist a basketball player in their practicing. The project hangs directly on the basketball rim and automatically rotates to find the player on the court. Once the player is detected, the automated basketball return system (ABRS) stays focused in the direction of the player so that any baskets successfully made will be funneled back to the player. When the player moves from center, IR motion detectors find which direction you moved to and rotates accordingly, until the player is focused in front of the funnel again. If at any time the player is absent from …

Rfid Modeling, Characterization, And Optimization, Joseph A. Cudrnak

Electrical Engineering

Passive RFID tags may be used to transmit a message to a reader. This technology is useful for many applications, including inventory systems. However, due to electromagnetic cancellation on conductive surfaces, the reader cannot detect RFID tags placed directly on conductive objects. Using tag characterization in an RF anechoic chamber and modeling in HFSS, three types of Omni ID tags were characterized and a design was proposed to maximize signal power delivered to the reader.

Meshscan: Performance Of Passive Handoff And Active Handoff, Yin Chen, Karol Kowalik, Mark Davis

Conference papers

A core problem of fast handoff is when handoff should perform and which Mesh Node (MN) should associated with. We have developed a fast handoff management scheme called MeshScan to provide a novel use of channel scanning latency, by employing open system authentication in both Passive Handoff and Active Handoff. This scheme comprises three steps: firstly a client device takes advantage of the Wireless Mesh Network (WMN) architecture to maintain a list of active MNs. Secondly MeshScan Handoff Sensor performs handoff when it receives a disassociation management frame from the serving MN or when the measured signal strength from the …

Design And Characterization Of A 1-Watt Driver Amplifier For Wireless Infrastructure, Chin-Leong Lim

Chin-Leong Lim

Variable gain amplifiers (VGA) find application in RF systems wherever the signal amplitude must be varied in reaction to a changing environment. Transmitters' driver stage utilize VGAs to conserve power under good propagation conditions and to minimize interference to adjacent sites. Cellular base-station receivers use VGAs in the 2nd/3rd stage LNA to prevent mixer/DAC overloading. Commercially available L-band VGA devices require 14 to 19 external components and have modest linearity-to-power consumption ratio (OIP3 / Pdc). To achieve the industry's lowest component count and best linearity-to-power ratio, we developed a highly integrated VGA module from 0.25 x 3900 um enhancement-mode Pseudomorphic …

Meshscan: Fast And Efficient Handoff In Ieee802.11 Mesh Networks, Yin Chen, Mark Davis

Conference papers

Handoff delay is one of the major problems in Wireless Mesh Network (WMN) that needs to be solved in order to allow time-critical and real-time applications run continuously during handoff. We have developed a fast handoff scheme called MeshScan to provide a novel use of channel scanning latency by employing open system authentication. This scheme comprises two steps: firstly a client device takes advantage of the WMN architecture to maintain a list of active mesh nodes. Secondly when handoff is required, a client transmits Authentication Request frames to all mesh nodes (MNs) from the list instead of broadcasting Probe Request …

Influence Of Solar Heating On The Performance Of Integrated Solar Cell Microstrip Patch Antennas, Maria Roo Ons, S. Shynu, M Seredynski, Max Ammann, Sarah Mccormack, Brian Norton

Articles

The integration of microstrip patch antennas with photovoltaics has been proposed for applications in autonomous wireless communication systems located on building façades. Full integration was achieved using polycrystalline silicon solar cells as both antenna ground plane and direct current power generation in the same device. An overview of the proposed photovoltaic antenna designs is provided and the variation characterised of the electromagnetic properties of the device with temperature and solar radiation. Measurements for both copper and solar antennas are reported on three different commercial laminates with contrasting values for thermal coefficient of the dielectric constant.

Directional Dual-Band Slot Antenna With Dual-Bandgap High-Impedance-Surface Reflector, Xiulong Bao, Giuseppe Ruvio, Max Ammann

Articles

A compact dual-band high-impedance-surface EBG structure is employed as a reflector for a dual-band annular-slot antenna. The reflector comprises an array of miniaturized EBG cells which utilizes square patches augmented by four S-shaped corrugated arms to reduce the resonant frequency of the proposed EBG structure. In order to broaden the bandwidth and adjust the frequency ratio for the dual-band EBG structure, a log-periodic spacing between the S-shaped strips is introduced. The combination of microstrip-fed annular slot and EBG reflector provides directional properties for both frequency bands with reduced size and low-profile.

An Experimental Study Of The Impact Of Using Multi-Radio In Wlan Mesh Networks, Chenzhe Zhang, Karol Kowalik, Mark Davis

Conference papers

Next-generation wireless mobile communications will be driven by converged networks that integrate disparate technologies and services. Wireless Mesh Networks (WMNs) are expected to be one of the next generation of wireless interconnection technologies, providing flexible high bandwidth wireless backhaul over large geographical areas. While single radio mesh nodes operating on a single channel suffer from capacity constraints, equipping mesh routers with multiple radios using multiple non-overlapping channels can significantly alleviate the capacity problem and increase the aggregate bandwidth available to the network. However, it is well known that multi-radio Mesh platforms face many limitations such as interference, radiation leakage, crosstalk …

A Study On The Effect Of Random Placement And Orientation On The Resonance Of Multiple Split Ring Resonators, Michael Buscher

Electrical Engineering Undergraduate Honors Theses

This thesis project experimentally studies the effect of placing split-ring oscillators (SRR) in a non-periodic arrangment with random orientation. This is contrary to typical structures which are simulated as a single unit cell with a periodic boundry condition to emulate an infinite array of SSR's. Samples are measured using a near-field free-space measurement system with full Thru, Reflect, Line (TRL) calibration and the application of time domain gating. Results, in the form of scattering (S) parameters, are compared with previous measurments of periodic SRR structures in order to study the influence, if any, of periodicity in the frequency response of …

The Navigation Potential Of Ground Feature Tracking, Guner Mutlu

Theses and Dissertations

This research effort examines the reduction of error in inertial navigation aided by vision. This is part of an effort focused on navigation in a GPS denied environment. The navigation concept examined here consists of two main steps. First, extract the position of a tracked ground object using vision and geo-locate it in 3 dimensional navigation frame. In this first step multiple positions of the UAV are assumed known; think of a synthetic aperture. The only information about the tracked ground objects/features is the unit vector that points to the objects from the center of the camera. Two such vectors …

Simulation Of Mc-Ds-Cdma-System Based On: Multi-Wavelets Transform Over Wireless Channel, Amean Al_Safi

Amean S Al_Safi

In this paper a scheme was proposed to improve the performance form the Bit Error Rate (BER) view point for Multicarrier-Direct-Sequence-Code Division Multiple Access (MC-DS-CDMA) system in wireless channel. The conventional MC-DS-CDMA-system is based on Fast Fourier Transform (FFT). The proposed system was based on Multi-Wavelet transform (MWT). Simulation results are done in three different types of channels. Simulation shows that the proposed system outperforms the conventional system in addition to a coded version of the conventional system. Also the MC-DS-CDMA-system which is based on MWT achieves better performance with the same loss in bandwidth than the MC-DS-CDMA-system based on …

Mass-Market Designed-For-Cellular Mmics Can Be Gainfully Adapted For Use In Niche Applications On Different Frequencies, Chin-Leong Lim

Chin-Leong Lim

Due to semiconductor manufacturers’ near exclusive focus on high growth markets such as cellular and wireless data, very little commercial RND resource is expended on developing Microwave Monolithic Integrated Circuits (MMIC) for the lower-volume traditional wireless services such as aviation and land mobile, etc. To circumvent the dearth of MMICs in those under-served market segments, we intend to show how off-the-shelf cellular MMICs can be leveraged into non-cellular applications. For this purpose, a MMIC originally conceived as a 900 MHz 0.5W driver amplifier is redeployed to two dissimilar applications: (i) a high linearity Low Noise Amplifier (LNA) for the 400~520 …

Networks - I: An Instantiation Of Way Point Routing For Mobile Ad Hoc Networks, Waseem M. Arain, Sayeed Ghani

International Conference on Information and Communication Technologies

Mobile ad hoc networks are increasingly finding their existence in the marketplace heading to a new paradigm of pervasive computing. However there are many areas open to research in the field. Due to node mobility resulting in an ever-changing network topology, conventional routing methods cannot be applied in MANETS. Therefore, this is one of the core areas of research. Researchers are challenged to design protocols that can potentially scale to anything from thousand to tens of thousands of nodes and to reduce the route discovery latency. In this paper a different instantiation of way point routing (WPR) model is proposed, …

Randomcast: An Energy-Efficient Communication Scheme For Mobile Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das

Electrical and Computer Engineering Faculty Publications

In mobile ad hoc networks (MANETs), every node overhears every data transmission occurring in its vicinity and thus, consumes energy unnecessarily. However, since some MANET routing protocols such as dynamic source routing (DSR) collect route information via overhearing, they would suffer if they are used in combination with 802.11 PSM. Allowing no overhearing may critically deteriorate the performance of the underlying routing protocol, while unconditional overhearing may offset the advantage of using PSM. This paper proposes a new communication mechanism, called RandomCast, via which a sender can specify the desired level of overhearing, making a prudent balance between energy and …

Design Of Acousto-Optic Chaos Based Secure Free-Space Optical Communication Links, Anjan K. Ghosh, Pramode K. Verma, Samuel Cheng, Robert C. Huck, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

Electrical and Computer Engineering Faculty Publications

We discuss the design of an acousto-optic cell based free space optical communication link where the data beam is made secure through chaos encryption. Using external signal modulation of the diffracted light from a hybrid acousto-optic cell chaos (or directly via incorporation in the sound-cell driver's bias voltage) encryption of data is possible. We have shown numerically that decryption of the encoded data is possible by using an identical acousto-optic system in the receiver.

Digitally-Tunable Surface Acoustic Wave Resonator, Robert Russell Hay

Boise State University Theses and Dissertations

Surface acoustic wave (SAW) technology has been utilized in numerous research and commercial devices since the practical implementation was enabled by the availability of suitable photolithographic techniques in the 1970s. With the traditional approach to implementing these devices the frequency response is established during manufacture. This dissertation proposes a different approach to implementing a SAW device. The SAW structure is added to the top of an integrated circuit so that the frequency response can be digitally controlled and the peak resonant frequency can be varied. The approach is based on implementing a phase-controlled interface between the SAW transducer fingers and …

System Identification Of An On Orbit Spacecraft's Antenna Dynamics, Christopher M. Sylvester

Theses and Dissertations

As a result of previous efforts [Pachter, Barba, 2007] a tight control loop was designed to meet performance specifications while minimizing the feedback control system’s gains of a spacecraft mounted flexible antenna. Emphasis is now shifted to on orbit system identification of the antenna dynamics in order to increase nominal plant knowledge, estimate plant uncertainty bounds, as well as determine the disturbance band. Non-parametric system identification is undertaken. Knowledge of the plant dynamics along with the corresponding uncertainty bounds will provide for the design of a control system which meets the specifications (tracking and disturbance rejection) while at the same …

Performance Study Of A Cross-Layer Optimization To The Dsr Routing Protocol In Wireless Mesh Networks, Mustafa Ramadhan, Mark Davis

Conference papers

A cross-layer modification to the DSR protocol is presented in this work which is intended to enhance the global throughput performance of wireless mesh networks. This modification involves the use of an access efficiency factor (which is a measure of the local availability of bandwidth at a node) as an alternative metric to the hop-count metric in order to allow for improved routing selection. The key feature of this modified route selection procedure is that it attempts to discover paths that have a large availability of bandwidth which can support high throughputs. In this work we have employed the OPNET …

A Graph-Based Approach To Symbolic Functional Decomposition Of Finite State Machines, Piotr Szotkowski, Mariusz Rawski, Henry Selvaraj

Electrical & Computer Engineering Faculty Research

This paper discusses the symbolic functional decomposition method for implementing finite state machines in field-programmable gate array devices. This method is a viable alternative to the presently widespread two-step approaches to the problem, which consist of separate encoding and mapping stages; the proposed method does not have a separate decomposition step instead, the state's final encoding is introduced gradually on every decomposition iteration. Along with general description of the functional symbolic decomposition method's steps, the paper discusses various algorithms implementing the method and presents an example realisation of the most interesting algorithm. In the end, the paper compares the results …

Synthetic Aperture Radar Imaging Simulated In Matlab, Matthew Schlutz

Master's Theses

This thesis further develops a method from ongoing thesis projects with the goal of generating images using synthetic aperture radar (SAR) simulations coded in MATLAB. The project is supervised by Dr. John Saghri and sponsored by Raytheon Space and Airborne Systems. SAR is a type of imaging radar in which the relative movement of the antenna with respect to the target is utilized. Through the simultaneous processing of the radar reflections over the movement of the antenna via the range Doppler algorithm (RDA), the superior resolution of a theoretical wider antenna, termed synthetic aperture, is obtained. The long term goal …

A Highly Abstracted Method Of Fpga-Based Development For Secondary Surveillance Radar Transpond Detection, James Penn Watt

Master's Theses

Traditional FPGA-based digital design is based on writing hardware definition language (HDL) code from scratch. Time to market, cost of development, and the level of training required for designers all can be reduced with a simplified and abstracted design strategy. This project intends to demonstrate a graphical user interface (GUI) layer of abstraction on top of existing commercially produced design aids including MATLAB, Simulink, and Xilinx System Generator. This project performs and demonstrates a specific implementation example of a Secondary Surveillance Radar (SSR) message decoder as proof-of-concept for the abstracted design method. The abstracted digital design methods shown in this …

Probability Density Functions For Snir In Ds-Cdma, David W. Matolak

Faculty Publications

Analytical expressions for the probability density function of block-wise signal-to-noise-plus-interference ratio for both synchronous and asynchronous direct-sequence spread spectrum code-division multiple access systems are developed, for equal average energy signals on the Gaussian and Rayleigh flat fading channels. Using the standard Gaussian approximation for multi-user interference, accurate density approximations are obtained, which agree very well with computer simulation results.

Preliminary Study Based On The Ddscat Software To Explore Increasing The Contrast Of Breast Tumors For Microwave Imaging, Rachel Megee

Electrical Engineering Undergraduate Honors Theses

Microwave technology is being researched for its capabilities to detect breast tumors less painfully and at earlier stages. It is necessary to have a large contrast between cancerous and healthy tissue when the microwaves are reflected off the breast tissue. To model the increasing contrast between cancerous breast tissue and healthy breast tissue, the DDSCAT code is investigated for its capabilities and analyzed for its accuracy in scattering calculations. The DDSCAT is used to model homogenous and inhomogeneous targets. Simulations of the scattering field by the homogeneous and inhomogeneous targets are conducted and compared to Mie theory calculations for accuracy. …

Computational Modeling Of The Internal Structure In The Breast, Jordan Greenlee

Electrical Engineering Undergraduate Honors Theses

Many researchers who are using microwave modality in the area of breast cancer detection employ oversimplified models of the internal structure of the breast. Use of engineered or biologically inaccurate models could render inaccurate results. Therefore, a mathematical biological model is implemented in this work and aims to bridge the gap between biologists and engineers. The results of the proposed breast duct model show that older women have smaller breast ducts leading to less dense breasts, which is in agreement with medical knowledge. Also, younger women have larger breast ducts leading to more dense breasts which are consistent with the …

Target Tracking Using Various Filters In Synthetic Aperture Radar Data And Imagery, Jessica L. Kiefer

Master's Theses

This thesis explores the use and accuracy of several discrete-time image filters for the purpose of target tracking in Synthetic Aperture Radar imagery. Both extended targets and point targets are used for tracking, showing the need for different types of filters for each target type.

Monte Carlo analysis is performed on the results of the extended target filter results to determine the absolute mean-squared error between the filter prediction of the target centroid and the actual location of the target centroid. Two different filters were chosen for the extended target: Kalman and H Infinity.

Both the Kalman and H Infinity …

Low Power Fft Processor Design Considerations For Ofdm Communications, David Layne Rushforth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Today's emerging communication technologies require fast processing as well as efficient use of resources. This project specifically addresses the power-efficient design of an FFT processor as it relates to OFDM communications such as cognitive radio. The Fast Fourier Transform (FFT) processor is what enables the efficient modulation in OFDM. As the FFT processor is the most computationally intensive component in OFDM communication, the power efficiency improvement of this component can have great impacts on the overall system. These impacts are significant considering the number of mobile and remote communication devices that rely on limited battery-powered operation. This project explores current …

Text Categorization Based On Apriori Algorithm's Frequent Itemsets, Prathima Madadi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Automatic Text categorization is the task of assigning an electronic document to one or more categories, based on its contents. There are many known techniques to efficiently solve categorization problems. Typically these techniques fall into two distinct methodologies which are either logic based or probabilistic. In recent years, many researchers have tried approaches which area hybrid of these two methodologies.

In this thesis, we deal with document categorization using Apriori Algorithm. The Apriori algorithm was initially developed for data mining and basket analysis applications in the relational databases. Although the technique is logic based, it also relies on the statistical …

Dynamic Network Formation Using Ant Colony Optimization, Steven C. Oimoen

Theses and Dissertations

Military and industry are moving toward every device being network enabled and connected for reliable availability of communication and information. To make this type of system a reality, the devices must be capable of forming a network topology on their own in a dynamic environment to ensure that the correct information reaches a desired location and on-time. This research presents three contributions for solving highly dynamic (i.e. drastic change within the network) Multi-commodity Capacitated Network Design Problems (MCNDPs) resulting in a distributed multi-agent network design algorithm. The first contribution incorporates an Ant Colony Optimization (ACO) algorithm Ant Colony System (ACS) …

Using A Multiobjective Approach To Balance Mission And Network Goals Within A Delay Tolerant Network Topology, Anthony L. Larweck

Theses and Dissertations

This thesis investigates how to incorporate aspects of an Air Tasking Order (ATO), a Communications Tasking Order (CTO), and a Network Tasking Order (NTO) within a cognitive network framework. This was done in an effort to aid the commander and or network operator by providing automation for battlespace management to improve response time and potential inconsistent problem resolution. In particular, autonomous weapon systems such as unmanned aerial vehicles (UAVs) were the focus of this research This work implemented a simple cognitive process by incorporating aspects of behavior based robotic control principles to solve the multi-objective optimization problem of balancing both …

Implementation Of Collaborative Rf Localization Using A Software-Defined Radio Network, Augustine A. Honore

Theses and Dissertations

This thesis investigates the use of collaboration between sensor nodes that were tasked with localizing a radio frequency emitter. Localization is a necessary component for dynamic spectrum access. Using a set of software-defined radios as our sensors and a received signal strength-based maximum likelihood localization algorithm, we successfully localized transmitting nodes based on their received signal strength. Our experiment was conducted outdoors using a flexible topology that could be shaped into 21 sub-topologies that varied in size, and orientation with respect to the transmitters. This was made possible through application of a time shift concept and a post-processing technique. We …