It has been estimated that data traffic from the different mobile devices that range from smartphones to machine-to-machine (M2M) devices will exceed 15.9 exabyte per month by the year 2018. With this immense data growth, the current wireless communication systems suffer from the scarcity of the radio spectrum and eventually...
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...
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...
This research presents the design of three nonlinear model predictive controllers (NMPCs) for floating oscillating water column (OWC) wave energy converters (WECs) array to maximize generated power, augmented with the control of the high-speed stop valves (HSSVs). Key to this design is the development of a high-fidelity discretized model for...
Converting energy from ocean waves is a challenging area for control theory application because of the nonlinear dynamics in various time scales. Generally, wave energy converter (WEC) control is applied in order to maximize power absorption, in the most common wave conditions, and subject to the devices’ physical constraints. Commonly,...
An accurate state estimation plays an essential role in power system operation and planning in energy management systems. However, existing multi-area state estimation researches have not focused on the importance of system clustering. The clustering mechanism divides or partitions a system according to user-defined criteria. Few published research works have...
In this dissertation, we explored multiple coding techniques to reduce energy consumption, improve performance, and secure wireless sensor networks specifically and ad-hoc networks in general. With the introduction of Internet of Things (IoT) and 5G technologies, wireless sensor networks are quickly emerging as an important and key technology in the...
As the power system grows larger and more complex, real-time monitoring and control become very significant in order to achieve reliable operation of the power system. Before any security assessment can be made or control actions are taken, the reliable estimate of the existing state of the system must be...
Massive Multiple-User Miltiple-Input Multiple-Output (MU-MIMO) wireless communication systems incorporate promising advanced strong technologies for upcoming 5G communications. To obtain some of the high spectrum and energy e ciencies bonuses brought by MU-MIMO systems, the ability to obtain Channel State information, especially on the receiver side (CSI), is important. To minimize...
In wireless communication, channel state information (CSI) is essential for data detection. Fast fading coefficients estimation is important in order to acquire accurate CSI. Kalman filters (KF) are widely used for real time parameter estimation and can be used to estimate the fast fading coefficients of a mobile communication channel....
Massive MIMO is a promising technique for future 5G communications due to its high spectrum and energy efficiency. To realize its potential performance gain, accurate channel state information at transmitter side (CSIT) is essential. Frequency division duplex (FDD) is widely employed by the most cellular systems today. However, it requires...
Due to the popularity of electronically controlled loads and the widespread use of alternative energy sources such as wind turbines and solar cells, the power quality at the distribution level must be carefully monitored. One of the many different means to monitor power quality is through frequency measurements. Nonlinearities cause...
Continues-Time (CT) Delta-Sigma (ΔΣ) Analog-to-Digital Converters (ADCs) have one important constrain, namely the excess loop delay. Most previous excess lop delay compensation methods need to know the exact value of the excess loop delay in advance. However, the value of the excess loop delay is a uniformly distribution random variable....
The broadband wireless interference in a computer platform is resulted by multiple electro-magnetic emission sources. This non-Gaussian interference is proved to be double-sided K-distributed in previous research. With the limitation of transmission power and dimension of the device, interference mitigation is an efficient way to improve received signal bit error...
Wave energy converter (WEC) devices are complicated systems containing hydrodynamic, mechanical, and electrical elements. WEC design efforts are primarily focused in the time-domain, using frequency-based energy analyses and numerical problem solving approaches that are staples in hydrodynamic design efforts to form the basic information set used in these time-domain development...
An improved robot manipulator decentralized non-linear adaptive
controller that performs well in the presence of disturbances with
unknown parameters and non-linearities is presented in this work.
The proposed decentralized adaptive structure is a modification of
the controller developed by Seraji [13-17] and is characterized by an
auxiliary signal that compensates...
A new algorithm is proposed which provides a sub-optimum near-far resistant
pattern for correlation with a known signal in a spread-spectrum multiple access
environment with additive white gaussian noise (AWGN). Only the patterns and
respective delays of the K-1 interfering users are required. The technique does not
require the inversion...
A new decentralized nonlinear controller for Robot Manipulators is
presented in this thesis. Based on concepts of Lyapunov stability theory and
some control ideas proposed in [3]-[7], we obtain continuous nonlinear
decentralized control laws which guarantee position and velocity tracking to
within an arbitrarily small error.
Assumptions based on physical...
A mathematical model of Limiting Dilution Analysis for two limiting
parameters is presented and investigated. Limiting Dilution Analysis is a microbiological
cell assay developed for immunological application. In the given
case we deal with the interaction between B lymphocytes, macrophage derived
factor and T-independent antigens. The state of the art...
Long bridges tend to develop large deformations under the
action of intense dynamical loads such as wind or earthquakes.
Unless these deformations are controlled in some fashion, the
structure might suffer damage or even collapse. One possible
solution to this problem is to apply external forces to the
bridge through...
An adaptive decentralized nonlinear controller for a robot manipulator
is presented in this thesis. Based on the adaptive control schemes designed
by Seraji [18], Dai [30], and Jimenez [31], we redesigned and further
simplified the control algorithm and, as a consequence, we achieved better
path tracking performance.
The proposed adaptive...
Recent technical progress has made new forms of controller
implementations on computers possible. Especially the technique of Fuzzy Logic
Control has found a growing number of applications. Also the development of fast
A/D converters has made the acquisation of data with vision based systems
possible. In this project we combine...
The purpose of this thesis is to apply the wavelet transform WT to
multiresolution structures for analyzing the information content of images based on
multiresolution signal decomposition of the wavelet representation. The advantage
of the wavelet transform is the fact that it uses different building blocks than the
Fourier's sines...
IS-95, an interim standard proposed for future digital personal communications
systems, uses two levels of encoding of digital data for error control and compatibility
with code-division multiple access (CDMA) transmission. The data is first
convolutionally encoded and the resulting symbols are interleaved and then groups are
encoded as orthogonal Walsh...
An extremely important area that has enabled or will enable many of the
digital video services and applications such as VideoCD, DVD, DVC, HDTV, video
conferencing, and DSS is digital video compression. The great success of digital video
compression is mainly because of two factors. The state of the art...
This dissertation presents the continued study of a
non-iterative decision feedback (DF) receiver/decoder
design and its application to cellular communications or
wireless local loop systems based on the IS-95(-A)
standard of the Telecommunications Industry Association
and also Personal Communications Services systems based on
the American National Standards Institute standard J-STD-...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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 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
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...
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...
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...
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...
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...
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...
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...
As the fifth generation of mobile communication systems (5G) is being deployed, massive multiple-input multiple-output (MIMO) serves as one of its enabling technologies where reliable and ultra low latency communications are achieved while being power and spectrum efficient. This thesis studies the security aspect of massive MIMO system from the...
Wave energy is one of the most promising renewable energy sources. Thus, research in this field has increased substantially over the last decade. However, significant costs associated with development and maintenance have so far impeded the implementation of commercially viable projects. Furthermore, the hydrodynamic interactions between water and prototypes meant...
Wave energy is a potentially important renewable clean source of energy that can help solve the energy demand throughout the world. A great deal of research has been conducted in the last few decades and it is now reaching the point of full implementation. In order to compete with other...
Ocean Wave Energy Converters (WECs) are of interest around the globe as global economies begin to shift their interest to renewable forms of energy. However, the devices are costly to construct–a quality that can be relieved through proper modeling, control, and implementation. This paper presents the numerical and hybrid simulation...