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Full-Text Articles in Engineering
Bio-Inspired Optimization Of Ultra-Wideband Patch Antennas Using Graphics Processing Unit Acceleration, Brian Vyhnalek
Bio-Inspired Optimization Of Ultra-Wideband Patch Antennas Using Graphics Processing Unit Acceleration, Brian Vyhnalek
ETD Archive
Ultra-wideband (UWB) wireless systems have recently gained considerable attention as effective communications platforms with the properties of low power and high data rates. Applications of UWB such as wireless USB put size constraints on the antenna, however, which can be very dicult to meet using typical narrow band antenna designs. The aim of this thesis is to show how bio-inspired evolutionary optimization algorithms, in particular genetic algorithm (GA), particle swarm optimization (PSO) and biogeography-based optimization (BBO) can produce novel UWB planar patch antenna designs that meet a size constraint of a 10 mm 10 mm patch. Each potential antenna design …
Evaluation And Comparison Of Mac Protocols In Wireless Sensor Networks, Sharmila Kollipara
Evaluation And Comparison Of Mac Protocols In Wireless Sensor Networks, Sharmila Kollipara
ETD Archive
Wireless sensor network applications call for different kinds of network protocols at different levels of the network stack based on application requirements. A number of medium access control (MAC) protocols have been proposed in the literature. Evaluation of most of these MAC protocols have typically been based on simulation, and while such simulation provides interesting insight into the behavior of these protocols, artifacts caused by behavior of hardware is ignored. Further more, MAC protocols are usually evaluated by comparing the new protocol with others based on one or two metrics, the ones that determined the design decisions for the protocol …
Implementation And Evaluation Of A Tdma Based Protocol For Wireless Sensor Networks, Robert M. Fiske
Implementation And Evaluation Of A Tdma Based Protocol For Wireless Sensor Networks, Robert M. Fiske
ETD Archive
When evaluating MAC layer network protocols for wireless sensor networks performing simulations of a protocol's operation can provide great insight into the performance of the protocol. In order to prove that a protocol will work in a real setting and not just at the theoretical level, however, there is no substitute for evaluation with a physical implementation. This thesis discusses a physical implementation and evaluation of the Many-to-One-Sensor-to-Sink (MOSS) MAC layer protocol for sink based wireless sensor networks using the MAC Layer Architecture for TinyOS. MOSS is a Time Division Multiple Access (TDMA) based protocol first proposed in an earlier …
Experimental Study Of Cooperative Communication Using Software Defined Radios, Murali Krishna Marunganti
Experimental Study Of Cooperative Communication Using Software Defined Radios, Murali Krishna Marunganti
ETD Archive
The aim of this thesis is to implement and test a real time wireless communication environment. Cooperative Communication is one of the methods by which a reliable communication can be obtained. This is performed using a Software Defined Radio. The received output is compared with the actual signal that is transmitted over the wireless channel. The wireless communications are often hindered by the noisy environments and make the system unreliable. The interference from neighboring nodes also poses a major disadvantage. There is a necessity to improve the performance of the system where the neighbor nodes can work in coordination with …
Experimental Study Of Multirate Margin In Software Defined Multirate Radio, Tianning Shen
Experimental Study Of Multirate Margin In Software Defined Multirate Radio, Tianning Shen
ETD Archive
Due to the recent development of spectrally-efficient modulation schemes, IEEE 802.11 Wifi and IEEE 802.16 WiMax radios support wireless communication at multiple bit rates. While high-rate transmission allows delivering more information in less time, the corresponding performance improvement is less than expected due to the PHY- and MAC-layer overheads, imposed by the 802.11/16 standards. This is particularly true in wireless ad hoc networks as there exist rate-distance and rate-hop count tradeoffs. The concept of multi-rate margin is proposed in this thesis, which exploits the difference in communication characteristics at different rates and serves as the fundamental ingredient for an opportunistic …
Multihop Transmission Opportunistic Protocol On Software Radio, Sachin C. Hirve
Multihop Transmission Opportunistic Protocol On Software Radio, Sachin C. Hirve
ETD Archive
The need of high speed communication motivates us to use high bit rate communication to transmit more information in as little time as possible. However, MAC layer protocol overheads dominate the transmission capability particularly at high rates and hinder high speed transmission. Opportunistic transmission has been proposed to help to overcome this disadvantage by transmitting packets back-to-back without inter-packet delays. Though this approach alleviates the problem in single-hop wireless LAN scenario, it doesn't help in multi-hop networks. This thesis presents an approach for multi-hop wireless networks, which is named as Multi-hop Transmission OPportunity (MTOP). It achieves better performance by ensuring …
Tracking In Wireless Sensor Network Using Blind Source Separation Algorithms, Anil Babu Vikram
Tracking In Wireless Sensor Network Using Blind Source Separation Algorithms, Anil Babu Vikram
ETD Archive
This thesis describes an approach to track multiple targets using wireless sensor networks. In most of previously proposed approaches, tracking algorithms have access to the signal from individual target for tracking by assuming (a) there is only one target in a field, (b) signals from different targets can be differentiated, or (c) interference caused by signals from other targets is negligible because of attenuation. We propose a general tracking approach based on blind source separation, a statistical signal processing technique widely used to recover individual signals from mixtures of signals. By applying blind source separation algorithms to mixture signals collected …
High Intensity Laser Power Beaming For Wireless Power Transmission, Daniel Edward Raible
High Intensity Laser Power Beaming For Wireless Power Transmission, Daniel Edward Raible
ETD Archive
This paper describes work supporting the development of a high intensity laser power beaming (HILPB) system for the purpose of wireless power transmission. The main contribution of this research is utilizing high intensity lasers to illuminate vertical multi-junction (VMJ) solar cells developed by NASA-GRC. Several HILPB receivers are designed, constructed and evaluated with various lasers to assess the performance of the VMJ cells and the receiver under a variety of conditions. Several matters such as parallel cell back-feeding, optimal receiver geometry, laser wavelength, non-uniform illumination and thermal effects at high intensities are investigated. Substantial power densities are achieved, and suggestions …