This thesis presents a channelized digital receiver design for UWB sytems in a multipath indoor environment. The UWB technology has been used for commercial and military purposes due to a number of advantages such as low-power consumption, noise-like and carrier free. The energy of UWB signal is spread over a...
Creating intelligent robotics is at the cutting edge of technology. Unmanned aerial vehicles (UAV) are of particular interest for surveillance applications. UAVs have the potential to provide quick and cheap aerial data that would be difficult to obtain by conventional means. UAVs also have the ability to navigate without being...
Transmission over wireless networks presents multiple technical challenges due to
noise, interference, fading, power constraints and bandwidth limitation. Different
solutions have been propposed to overcome these issues and some of them are
treated here. Cooperative diversity has been proposed as an implementation for
networks where terminals are restricted to using...
Radio frequency (RF) power amplifiers (PA) are the most power consuming components of a mobile communications unit. They are used to convert the DC power from the battery into RF power delivered to the antenna. In a cell phone it becomes very important to use highly efficient power amplifiers, such...
High data rate transmission has become an important challenge in today digital communication systems. One of the most difficult problems faced by engineers is to transmit data at sufficiently high rates through fading channels. This is the main motivation for the research presented herein. In this thesis, we investigate a...
There has been tremendous technological advancement in the area of high-speed indoor wireless local area networks (WLAN's) in recent years. All the existing tech- nologies such as IEEE 802.11a,b are bandwidth limited and high powered systems. The challenge any wireless technology faces is to minimize both the power consumption and...
In modern telecommunication applications, the need for high-reliability and high data rate is important because of factors such as a higher demand in multimedia capability of mobile devices and the exponentially increasing number of subscribers. Wireless communications in today’s technology have many limitations due to channel imperfections, which result in...
Various methods and techniques have been introduced and applied to advance the state of the art of mobile wireless communications technology. For example, some techniques are applied to overcome the problem of multipath caused by the mobile environment. Multipath produces replicas of the wanted signal which arrive at the receiver...
This research explores the viability and effectiveness of using an inertial navigation system (INS) to control a beamforming array of microstrip patch antennas with the aim of reducing users' exposure to electromagnetic radiation. The system reduces radiated power directed toward a cellular phone user to below 10% of the total...
The imperfections of the propagation channel due to channel fading and the self-generated noise from the RF front-end of the receiver cause errors in the received signal in electronic communication systems. When network coding is applied, more errors occur because of error propagation due to the inexact decoding process. In...
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Mario E. Magaña
The imperfections of the propagation channel due to channel fading and
Recently, the demand for higher data rates of transmission has increased in
many wireless communication applications. Using multi-transmit and multi-receive
antennas has been shown to be a solution, since it can increase the channel capacity to
accommodate higher transmission rates. Among the popular techniques developed to
exploit the use of...
The decrease of switching times accompanied by the corresponding increase of
clock speeds and data rates, contributes to improve the overall system
computational performance. At the same time, they also affect wireless
communications due to an increment in the emissions of electromagnetic
radiation on the radio bands.
In this dissertation...
In networked control systems (NCS) information or packets usually flow from a
sensor or a set of sensors to a remotely located controller. Then the controller
processes the received information and sends a series of control commands to the
actuators through a communication network which could be either wireless or...
Modern applications in wireless communications systems demand the capability of high transmission rate. Engineers have to find optimum solutions to transmit the signal over fading environments. In this study, we propose the combination of space-time diversity techniques and optimum QAM constellation design, in order to further improve performance. Specifically, we...
A constant push from society for more information with richer content simultaneously available at the consumers fingertips have pushed the speeds of electronics to extremes. Bus lines on circuit boards responsible for data communication are being pushed to their limit to meet these demands. As data busses are pushed to...
The world's demand for energy is an ongoing challenge, which has yet to be overcome.
The efforts to find clean energy alternatives to fossil fuels have been hampered by the
lack of investment in technology and research. Among these clean energy alternatives
are ocean waves and wind. Wind power is...
Estimating the carrier frequency from a modulated waveform is one of the most important functions of a coherent signal receiver. Good performance and low bit error rates are obtained by coherent demodulation. Therefore, exact knowledge of the received signal carrier frequency is critical for communication systems. Also due to the...
Turbo codes have been used successfully for error correction in digital communications, however, their application to wireless mobile communications is still a fresh research topic. The objective of this thesis is to present a new solution that involves the usage of turbo codes, spatial diversity, and orthogonal complementary codes in...
This document investigates, justifies, designs, and simulates the application of a fuzzy logic controller/optimizer in a sawmill bucking system application that is the first production station where stems coming from the mountains are processed in a sawmill. One of the areas of success in the application of fuzzy logic is...
The widespread use of Wireless Local Area Networks (WLAN) and the desire for such products from different vendors to operate together has generated a movement towards standardization. Over the last decade, several organizations worldwide have researched and developed such standards, this includes the IEEE 802.11 committee. One of the important...