Systems and Communications Commons^™

Addressing/Exploiting Transceiver Imperfections In Wireless Communication Systems, Lihao Wang

Masters Theses 1911 - February 2014

This thesis consists of two research projects on wireless communication systems. In the first project, we propose a fast inphase and quadrature (I/Q) imbalance compensation technique for the analog quadrature modulators in direct conversion transmitters. The method needs no training sequence, no extra background data gathering process and no prior perfect knowledge of the envelope detector characteristics. In contrast to previous approaches, it uses points from both the linear and predictable nonlinear regions of the envelope detector to hasten convergence. We provide a least mean square (LMS) version and demonstrate that the quadrature modulator compensator converges.

In the second project, …

Simulating A Universal Geocast Scheme For Vehicular Ad Hoc Networks, Benjamin L. Bovee

Masters Theses 1911 - February 2014

Recently a number of communications schemes have been proposed for Vehicular Ad hoc Networks (VANETs). One of these, the Universal Geocast Scheme (UGS) proposed by Hossein Pishro-Nik and Mohammad Nekoui, provides for a diverse variety of VANET-specific characteristics such as time-varying topology, protocol variation based on road congestion, and support for non line-of-sight communication. In this research, the UGS protocol is extended to consider inter-vehicle multi-hop connections in intersections with surrounding obstructions along with single-hop communications in an open road scenario. Since UGS is a probabilistic, repetition-based scheme, it supports the capacity-delay tradeoffs crucial for periodic safety message exchange. The …

Audio-To-Optical Conversion And Transmission, Jason Moritz

Electrical Engineering

The purpose of this project is to understand free-space optical transmission of signals in the application of transmitting an audio signal. An audio signal will be taken from the headphone output of a computer and used to modulate a current source driving an LED and a laser diode. The optical signal will then be transmitted through free space as well as two different focal length lenses and converted back to an audio signal to measure any attenuation or gain in the original signal. My experimental results showed that the LED was able to transmit up to 10 dB more power …

Aether, Thomas Cameron, Kristine Colton, Daren Childers

Electrical Engineering

Aether is a RC-style autonomous air vehicle that utilizes GPS positioning along with a wireless communication system to achieve a computer-controlled flight.

This report will incorporate the acquisition, design, integration, implementation and testing phases of the UAV development. Furthermore a discussion of troubleshooting as well as improvements for future projects will be included.

Special Issue On Information Dissemination And New Services In P2p Systems, Min Song, Sachin Shetty, Wenbin Jiang, E. K. Park

Electrical & Computer Engineering Faculty Publications

Information dissemination is an important P2P application that has received considerable research attention in recent years. P2P information dissemination systems range from simple file sharing applications to more complex systems that allows users to securely and efficiently publish, organize, index, search, update and retrieve data in a distributed storage medium. For complex P2P information dissemination systems, there is a need for features which include security, anonymity, fairness, scalability, resource management, and organization capabilities. For effective information dissemination, following features of P2P systems and infrastructure need to be updated: distributed object location and routing mechanisms, novel approaches to content replication, caching …

Model-Driven Safety Analysis Of Closed-Loop Medical Systems, Miroslav Pajic, Rahul Mangharam, Oleg Sokolsky, David Arney, Julian M. Goldman, Insup Lee

Departmental Papers (CIS)

In modern hospitals, patients are treated using a wide array of medical devices that are increasingly interacting with each other over the network, thus offering a perfect example of a cyber-physical system. We study the safety of a medical device system for the physiologic closed-loop control of drug infusion. The main contribution of the paper is the verification approach for the safety properties of closed-loop medical device systems. We demonstrate, using a case study, that the approach can be applied to a system of clinical importance. Our method combines simulation-based analysis of a detailed model of the system that contains …

Special Issue On Wireless Sensor And Actuator Networks, Jiming Chen, Karl H. Johanson, Stephan Olariu, Ioannis Ch. Paschalidis, Ivan Stojmenovic

Computer Science Faculty Publications

( First paragraph) WIRELESS Sensor Networks (WSNs), in their various shapes and forms, have greatly facilitated and enhanced the automated, remote, and intelligent monitoring of a large variety of physical systems. These networks consist of a large number of typically small devices, each incorporating sensing, processing, and wireless communications capabilities. Their use has penetrated a plethora of application domains from industrial and building automation, to environmental, wildlife, and health monitoring.

Separation Distance Reduction In Mimo Systems Using End-Fire Antenna Arrays, Amean Al_Safi

Amean S Al_Safi

The main problem in Multiple Input-Multiple Output (MIMO) systems is the separation distance between antennas which must be greater than or equal to half wavelength. Satisfying this separation is difficult or impossible especially at mobile communication, therefore this paper study the capability to reduce these separation distance by using End-Fire antenna arrays. Each antenna at the transmitter and receiver side is replaced by a set of antennas work as an array with a radiation pattern directed toward the axes of the arrays. The separation between elements in these arrays is fixed at quarter wavelength in order to have one main …

Contextualized Mobile Support For Learning By Doing In The Real World, Ray Bareiss, Natalie Linnell, Martin Griss

Ray Bareiss

This research addresses the use of mobile devices with both embedded and external sensors to provide contextualized help, advice, and remediation to learners engaged in real-world learn-by-doing tasks. This work is situated within the context of learning a complex procedure, in particular emergency responders learning to conduct urban search and rescue operations. Research issues include the design and delivery of contextualized performance support and the inferring of learner actions and intentions from sensor data to ensure that the right support is delivered just in time, as it is relevant to what the learner is doing.

Fpga Implementation Of Pipeline Digit-Slicing Multiplier-Less Radix 2 2 Dif Sdf Butterfly For Fast Fourier Transform Structure, Yazan Samir, Rozita Teymourzadeh, Masuri Othman, Shabiul Islam

Dr. Rozita Teymourzadeh, CEng.

Optimised Toolbox For The Design Of Rotary Reluctance Motors, Grace I, Rozita Teymourzadeh, Bright S, Aravind Cv

Dr. Rozita Teymourzadeh, CEng.

Link Scheduling In Multi-Transmit-Receive Wireless Networks, Hong-Ning Dai, Soung Chang Liew, Liqun Fu

Hong-Ning Dai

This paper investigates the problem of link scheduling to meet traffic demands with minimum airtime in a multitransmit-receive (MTR) wireless network. MTR networks are a new class of networks, in which each node can simultaneously transmit to a number of other nodes, or simultaneously receive from a number of other nodes. The MTR capability can be enabled by the use of multiple directional antennas or multiple channels. Potentially, MTR can boost the network capacity significantly. However, link scheduling that makes full use of the MTR capability must be in place before this can happen. We show that optimal link scheduling …

Exploring Security Improvement Of Wireless Networks With Directional Antennas, Hong-Ning Dai, Dong Li, Raymond Chi-Wing Wong

Hong-Ning Dai

There are a number of studies on using directional antennas in wireless networks. Many of them concentrate on analyzing the theoretical capacity improvement by using directional antennas. Other studies focus on designing proper Medium Access Control (MAC) protocols to improve the practical network throughput. There are few works on the security improvement using directional antennas. In this paper, we explore the benefits of directional antennas in security improvements on both singlehop and multi-hop wireless networks. In particular, we found that using directional antennas in wireless networks can significantly reduce the eavesdropping probabilities of both single-hop transmissions as well as multi-hop …

Tree-Based Partition Querying: A Methodology For Computing Medoids In Large Spatial Datasets, Kyriakos Mouratidis, Dimitris Papadias, Spiros Papadimitriou

Kyriakos MOURATIDIS

Besides traditional domains (e.g., resource allocation, data mining applications), algorithms for medoid computation and related problems will play an important role in numerous emerging fields, such as location based services and sensor networks. Since the k-medoid problem is NP hard, all existing work deals with approximate solutions on relatively small datasets. This paper aims at efficient methods for very large spatial databases, motivated by: (i) the high and ever increasing availability of spatial data, and (ii) the need for novel query types and improved services. The proposed solutions exploit the intrinsic grouping properties of a data partition index in order …

The Wireless Control Network: Synthesis And Robustness, Miroslav Pajic, Shreyas Sundaram, Jerome Le Ny, George J. Pappas, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. Traditional networked control schemes are designed with one of the nodes in the network acting as a dedicated controller, while the other nodes simply route information to and from the controller and the plant. We introduce the concept of a Wireless Control Network (WCN) where the entire network itself acts as the controller. Specifically, at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire …

A Linear Combination Of Heuristics Approach To Spatial Sampling Hyperspectral Data For Target Tracking, Barry R. Secrest

Theses and Dissertations

Persistent surveillance of the battlespace results in better battlespace awareness which aids in obtaining air superiority, winning battles, and saving friendly lives. Although hyperspectral imagery (HSI) data has proven useful for discriminating targets, it presents many challenges as a useful tool in persistent surveillance. A new sensor under development has the potential of overcoming these challenges and transforming our persistent surveillance capability by providing HSI data for a limited number of pixels and grayscale video for the remainder. The challenge of exploiting this new sensor is determining where the HSI data in the sensor's field of view will be the …

Mobile Map Browsers: Anticipated User Interaction For Data Pre-Fetching, Benjamin T. Weber

Electronic Theses and Dissertations

When browsing a graphical display of geospatial data on mobile devices, users typically change the displayed maps by panning, zooming in and out, or rotating the device. Limited storage space on mobile devices and slow wireless communications, however, impede the performance of these operations. To overcome the bottleneck that all map data to be displayed on the mobile device need to be downloaded on demand, this thesis investigates how anticipated user interactions affect intelligent pre-fetching so that an on-demand download session is extended incrementally. User interaction is defined as a set of map operations that each have corresponding effects on …

Directional Patch Antenna Array Design For Desktop Wireless Internet, Noah Snyder

Electrical Engineering

To improve desktop wireless internet access, two patch antenna configurations were investigated in order to find an alternative for a dipole antenna, which is commonly used for Wi-Fi access. A Linksys WMP54G pci-card wireless adapter was used to test three antennas for 802.11g communications. The standard WMP54G dipole antenna and two patch antenna configurations were tested for Wi-Fi signal strength. The antennas were also tested in Cal Poly’s anechoic chamber to obtain resonant frequency and gain measurements. A 2.437 GHz center frequency, 72 MHz bandwidth antenna consisting of a single microstrip patch was constructed. After the patch antenna was determined …

Self-Stabilizing Group Membership Protocol, Mahesh Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we consider the problem of partitioning a network into groups of bounded diameter.

Given a network of processes X and a constant D, the group partition problem is the problem of finding a D-partition of X, that is, a partition of X into disjoint connected subgraphs, which we call groups, each of diameter no greater than D. The minimal group partition problem is to find a D-partition {G1, ... Gm} of X such that no two groups can be combined; that is, for any Gi and Gj, where i ≠ j, either Gi U Gj is disconnected …

Data Routing In Multicore Processors Using Dimension Increment Method, Arpita H. Kadakia

UNLV Theses, Dissertations, Professional Papers, and Capstones

A Deadlock-free routing algorithm can be generated for arbitrary interconnection network using the concept of virtual channels but the virtual channels will lead to more complex algorithms and more demands of NOC resource.

In this thesis, we study a Torus topology for NOC application, design its structure and propose a routing algorithm exploiting the characteristics of NOC. We have chosen a typical 16 (4 by 4) routers Torus and propose the corresponding route algorithm. In our algorithm, all the channels are assigned 4 different dimensions (n0,n1,n2 & n3). By following the dimension increment method, we break the dependent route circles, …