Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 20 for “"ultrawideband"”.
-
Ultrawideband Indoor Location And Tracking System
… intruder location and tracking system with UltraWideBand (UWB) technology and use data compression and Constant False Alarm Rate (CFAR) techniques to improve the performance of the location system. Reliable and accurate indoor positioning requires a local replacement for GPS systems since …
-
Channel-coded time-hopping and direct-sequence ultrawideband systems
… for enhancing the achievable performance of UltraWideBand (UWB) systems. We commence by a rudimentary introduction to UWB systems, including a brief historical perspective of the field. Chapters 2 to 4 will then provide the designs of channel coded UWB systems with the aid of EXtrinsic …
-
Ultrawideband IEEE802.15.4a Cognitive Localization Methods for the 5G Environment
This thesis focuses on utilization of ultra-wideband (UWB) technology for cognitive localization in the fifth generation (5G) wireless environment that envisages seamless global connection of ubiquitous devices. This suggests the need for cognitive high-definition location-aware networks and …
-
An Ultrawideband Dual-Linear Polarization Feed for Solar Microwave Observation
… of these existing dishes with a single ultrawideband feed to cover 1-10GHz would improve observations, while adding a dual polarization capability could facilitate improved monitoring should there be future developments in spectrum usage. A feed with folded diamond-shaped elements in a …
-
Ultrawideband Channel Sounding Studies in Outdoor and Outdoor-Indoor Environments
Ultrawideband (UWB) is one of the most promising communication technologies in recent times with the promise of high data rates and spectral reuse. This work analyses the outdoor and outdoor-to-indoor propagating characteristics of the UWB pulse, which can be of the order of a few gigahertz in …
-
Design of Ultrawideband Digitizing Receivers for the VHF Low Band
The next generation of receivers for applications such as radio astronomy, spectrum surveillance, and frequency-adaptive cognitive radio will require the capability to digitize very large bandwidths in the VHF low band (30 to 100 MHz). However, methodology for designing such a receiver is not well …
-
Ultrawideband and Multi-state Reconfigurable Antennas with Sum and Difference Radiation Patterns
… of new pattern diversity antenna designs. Ultrawideband and frequency reconfigurable designs of pattern diversity antennas are desirable to help reduce the cost and increase the flexibility in applications of pattern diversity antennas. These two types of performances constitute the …
-
Experimental Investigation Of Ultrawideband Wireless Systems: Waveform Generation, Propagation Estimation, And Dispersion Compensation
<p>Ultrawideband (UWB) is an emerging technology for the future high-speed wireless communication systems. Although this technology offers several unique advantages like robustness to fading, large channel capacity and strong anti-jamming ability, there are a number of practical challenges which …
-
Simulation and Mathematical Tools for Performance Analysis of Low-Complexity Receivers
… (SDAR), Code Division Multiple Access (CDMA) and UltraWideband (UWB) communications technologies. A graphical-user-interface simulation tool has been developed to predict the link reliability performance of the SDAR services in the continental United States. Feasibility study of receiving both …
-
Nonlinear/electromagnetic co-simulation of microwaves and millimeter-waves links
… ultra-wideband link, the transmitting side of an ultrawideband link has been designed, and an interesting Front-End co-design technique application has been setup.
-
The Design and Modeling of Ultra-Wideband Position-Location Networks
Impulse-based Ultrawideband (UWB) is a form of signaling which uses streams of pulses of very short duration, typically on the order of a nanosecond. Impulse-based UWB systems possess the ability to fuse accurate position-location with low-data rate communication, and provide covertness for …
-
Design and Implementation of an Ultrabroadband Millimeter-Wavelength Vector Sliding Correlator Channel Sounder and In-Building Multipath Measurements at 2.5 & 60 GHz
… of frequencies and bandwidths in addition to the ultrawideband channels investigated in this work. This measurement system is also designed to be capable of characterizing both the magnitude and phase response of these wireless channels, which not only provides a more complete channel …
-
YSCAT Backscatter Distributions
<p>YSCAT is a unique ultrawideband microwave scatterometer developed to investigate the sea surface under a variety of environmental and radar parameters. The YSCAT94 experiment consisted of a six month deployment on the WAVES research tower operated by the Canada Center for inland Waters (CCIW). …
-
Improving the Specificity of Medical Ultrasound Imaging Using Scattering Spectrum Matching
… clutter artifacts. Modern ultrasound employs ultrawideband transducers with fractional bandwidths larger than 70% being typical. This provides the opportunity to improve the image quality using frequency compounding methods, which have been traditionally used in speckle reduction at the …
-
Electromagnetic Time-Reversal Imaging and Tracking Techniques for Inverse Scattering and Wireless Communications
… is known as `superresolution’. Moreover, under ultrawideband (UWB) operation, TR exhibits the distinctive property of `statistical stability’, which makes it an attractive technique for imaging in disordered media whose characteristics are not known deterministically (random media). Over the …
-
Miniaturised and reconfigurable planar filters for ultra-wideband applications
… reconfigurable planar microwave filters for ultrawideband applications. The project investigates some key design issues of reconfigurable filters, which are being observed constantly in the latest development and realisation of microwave filters. Both analytical and numerical methods are …
-
Self-concatenated coding for wireless communication systems
… concept.<br/>Application of SECCCs in both UltraWideBand (UWB) and state-of-the-art video-telephone schemes demonstrated its practical benefits.<br/><br/>In order to further exploit the benefits of the low complexity design offered by SECCCs we explored their application in a distributed …
-
Development of Low-power Wireless Sensor Nodes based on Assembled Nanowire Devices
… second part of this work, a multi-band hopping ultrawideband transmitter was designed to operate in three different frequency bands namely, 4.8 GHz, 6.4 GHz and 8.0 GHz. As a part of this effort, this thesis includes the design of a CMOS phase/frequency detector (PFD), a CMOS pseudo-random code …
-
Correlator for a Basis-Space Architecture Ultra-Wideband Receiver
Ultra Wideband (UWB) signals have great potential for high data transmission and precise location. However, their wide bandwidth and low signal to noise levels make UWB receiver design via traditional methods difficult. New receiver architectures have been proposed that rely on the correlation of …
-
On the Development of a Very Fast Simulator for TH-UWB Systems = Sobre el Desarrollo de un Simulador Rápido para los Sistemas TH-UWB
… low power. Unfortunately, in order to process ultrawideband signals, an extremely large sampling rate is mandatory. In a straightforward approach, with the constant sampling rate, the length of the array that contains the bit samples can be very large, depending on the relationship between the …