The demand for wireless data services has been dramatically growing over the last decade. This growth has been accompanied by a significant increase in the number of users sharing the same wireless medium, and as a result, interference management has become a hot topic of research in recent years. In this dissertation, we investigate feedback and transmitter cooperation as two closely related tools to manage the interference and achieve high data rates in several wireless networks, focusing on additive white Gaussian noise (AWGN) interference, X, and broadcast channels. We start by a one-to-many network, namely, the three-user multiple-input multiple-output (MIMO) Gaussian broadcast channel, where we assume that the transmitter obtains the channel state information (CSI) through feedback links after a finite delay. We also assume that the feedback delay is greater than the channel coherence time, and thus, the CSI expires prior to being exploited by the transmitter for its current transmission. Nevertheless, we show that this delayed CSI at the transmitter (delayed CSIT) can help the transmitter to achieve significantly higher data rates compared to having no CSI. We indeed show that delayed CSIT increases the channel degrees of freedom (DoF), which is translated to an unbounded increase in capacity with increasing signal-to-noise-ratio (SNR). For the symmetric case, i.e. with the same number of antennas at each receiver, we propose different transmission schemes whose achievable DoFs meet the upper bound for a wide range of transmit-receive antenna ratios. Also, for the general non-symmetric case, we propose transmission schemes that characterize the DoF region for certain classes of antenna configurations. Subsequently, we investigate channels with distributed transmitters, namely, Gaussian single-input single-output (SISO) K-user interference channel and 2×K X channel under the delayed CSIT assumption. In these channels, in major contrast to the broadcast channel, each transmitter has access only to its own messages. We propose novel multiphase transmission schemes wherein the transmitters collaboratively align the past interference at appropriate receivers using the knowledge of past CSI. Our achievable DoFs are greater than one (which is the channel DoF without CSIT), and strictly increasing in K. Our results are yet the best available reported DoFs for these channels with delayed CSIT. Furthermore, we consider the K-user r-cyclic interference channel, where each transmitter causes interference on only r receivers in a cyclic manner. By developing a new upper bound, we show that this channel has K/r DoF with no CSIT. Moreover, by generalizing our multiphase transmission ideas, we show that, for r=3, this channel can achieve strictly greater than K/3 DoF with delayed CSIT. Next, we add the capability of simultaneous transmission and reception, i.e. full-duplex operation, to the transmitters, and investigate its impact on the DoF of the SISO Gaussian K-user interference and M×K X channel under the delayed CSIT assumption. By proposing new cooperation/alignment techniques, we show that the full-duplex transmitter cooperation can potentially yield DoF gains in both channels with delayed CSIT. This is in sharp contrast to the previous results on these channels indicating the inability of full-duplex transmitter cooperation to increase the channel DoF with either perfect instantaneous CSIT or no CSIT. With the recent technological advances in implementation of full-duplex communication, it is expected to play a crucial role in the future wireless systems. Finally, we consider the Gaussian K-user interference and K×K X channel with output feedback, wherein each transmitter causally accesses the output of its paired receiver. First, using the output feedback and under no CSIT assumption, we show that both channels can achieve DoF values greater than one, strictly increasing in K, and approaching the limiting value of 2 as K→∞. Then, we develop transmission schemes for the same channels with both output feedback and delayed CSIT, known as Shannon feedback. Our achievable DoFs with Shannon feedback are greater than those with the output feedback for almost all values of K.

Container vessel motions need to be small when loading and offloading cargo while moored to wharfs. Waves and their reflections from structures can induce ship motions. These motions are characterized by six degrees of freedom, including translations of surge, sway, and heave and rotations of pitch, roll, and yaw. Monitoring and quantifying these motions offer a reference for design and selection of the mooring system and wharf types. To measure the six degrees of freedom motions of a container ship moored to a dock, a 1:50 scale model is moored to two types of dock, solid wall dock and pile supported dock. Irregular waves of TMA spectrum with various periods, heights, and directions are generated in the wave basin to induce the motions of the model container ship. Optical motion capturing cameras are used to measure and quantify the six degree of freedom motions. Results of the effects of wave period, significant wave height, and wave direction on the motion characteristics of the model container ship moored at the solid dock and a pile supported dock are described in detail. A numerical simulation called aNySIM is applied to numerically predict the motion characteristics of the container ship moored to a solid wall dock only. The physical model experimental results of solid dock are also compared with the numerical simulation. These comparisons indicate that the motion characteristics of the model container ship represent similar trends for both rotations and translations. The experimental and numerical prediction values of motions of the ship moored to a solid wall dock display the same tendencies while differing in magnitude.

Multiple-Input Multiple-Output (MIMO) systems are a pivotal solution for the significant enhancement of the band-limited wireless channels’ communication capacity. MIMO system is essentially a wireless system with multiple antennas at both the transmitter and receiver ends. Compared to the conventional wireless systems, the main advantages of the MIMO systems are the higher system capacity, more bit rates, more link reliability, and wider coverage area. All of these features are currently considered as crucial performance requirements in wireless communications. Additionally, the emerging new services in wireless applications have created a great motivation to utilize the MIMO systems to fulfil the demands these applications create. The MIMO systems can be combined with other intelligent techniques to achieve these benefits by employing a higher spectral efficiency. The MIMO system design is a multifaceted problem which needs both antenna considerations and baseband signal processing. The performance of the MIMO systems depends on the cross-correlation coefficients between the transmitted/received signals by different antenna elements. Therefore, the Electromagnetic (EM) characteristics of the antenna elements and wireless environment can significantly affect the MIMO system performance. Hence, it is important to include the EM properties of the antenna elements and the physical environment in the MIMO system design and optimizations. In this research, the MIMO system model and system performance are introduced, and the optimum MIMO antenna system is investigated and developed by considering the electromagnetic aspects within three inter-related topics: 1) Fast Numerical Analysis and Optimization of the MIMO Antenna Structures: An efficient and fast optimization method is proposed based on the reciprocity theorem along with the method of moment analysis to minimize the correlation among the received/transmitted signals in MIMO systems. In this method, the effects of the radio package (enclosure) on the MIMO system performance are also included. The proposed optimization method is used in a few practical examples to find the optimal positions and orientations of the antenna elements on the system enclosure in order to minimize the cross-correlation coefficients, leading to an efficient MIMO operation. 2) Analytical Electromagnetic-Theoretic Model for the MIMO Antenna Design: The first requirement for the MIMO antennas is to obtain orthogonal radiation modes in order to achieve uncorrelated signals. Since the Spherical Vector Waves (SVW) form a complete set of orthogonal Eigen-vector functions for the radiated electromagnetic fields, an analytical method based on the SVW approach is developed to excite the orthogonal SVWs to be used as the various orthogonal modes of the MIMO antenna systems. The analytic SVW approach is used to design spherical antennas and to investigate the orthogonality of the radiation modes in the planar antenna structures. 3) Systematic SVW Methodology for the MIMO Antenna Design: Based on the spherical vector waves, a generalized systematic method is proposed for the MIMO antenna design and analysis. The newly developed methodology not only leads to a systematic approach for designing MIMO antennas, but can also be used to determine the fundamental limits and degrees of freedom for designing the optimal antenna elements in terms of the given practical restrictions. The proposed method includes the EM aspects of the antenna elements and the physical environment in the MIMO antenna system, which will provide a general guideline for obtaining the optimal current sources to achieve the orthogonal MIMO modes. The proposed methodology can be employed for any arbitrary physical environment and multi-antenna structures. Without the loss of generality, the SVW approach is employed to design and analyze a few practical examples to show how effective it can be used for MIMO applications. In conclusion, this research addresses the electromagnetic aspects of the antenna analysis, design, and optimization for MIMO applications in a rigorous and systematic manner. Developing such a design and analysis tool significantly contributes to the advancement of high-data-rate wireless communication and to the realistic evaluation of the MIMO antenna system performance by a robust scientifically-based design methodology.

The demand for wireless data services has been dramatically growing over the last decade. This growth has been accompanied by a significant increase in the number of users sharing the same wireless medium, and as a result, interference management has become a hot topic of research in recent years. In this dissertation, we investigate feedback and transmitter cooperation as two closely related tools to manage the interference and achieve high data rates in several wireless networks, focusing on additive white Gaussian noise (AWGN) interference, X, and broadcast channels. We start by a one-to-many network, namely, the three-user multiple-input multiple-output (MIMO) Gaussian broadcast channel, where we assume that the transmitter obtains the channel state information (CSI) through feedback links after a finite delay. We also assume that the feedback delay is greater than the channel coherence time, and thus, the CSI expires prior to being exploited by the transmitter for its current transmission. Nevertheless, we show that this delayed CSI at the transmitter (delayed CSIT) can help the transmitter to achieve significantly higher data rates compared to having no CSI. We indeed show that delayed CSIT increases the channel degrees of freedom (DoF), which is translated to an unbounded increase in capacity with increasing signal-to-noise-ratio (SNR). For the symmetric case, i.e. with the same number of antennas at each receiver, we propose different transmission schemes whose achievable DoFs meet the upper bound for a wide range of transmit-receive antenna ratios. Also, for the general non-symmetric case, we propose transmission schemes that characterize the DoF region for certain classes of antenna configurations. Subsequently, we investigate channels with distributed transmitters, namely, Gaussian single-input single-output (SISO) K-user interference channel and 2×K X channel under the delayed CSIT assumption. In these channels, in major contrast to the broadcast channel, each transmitter has access only to its own messages. We propose novel multiphase transmission schemes wherein the transmitters collaboratively align the past interference at appropriate receivers using the knowledge of past CSI. Our achievable DoFs are greater than one (which is the channel DoF without CSIT), and strictly increasing in K. Our results are yet the best available reported DoFs for these channels with delayed CSIT. Furthermore, we consider the K-user r-cyclic interference channel, where each transmitter causes interference on only r receivers in a cyclic manner. By developing a new upper bound, we show that this channel has K/r DoF with no CSIT. Moreover, by generalizing our multiphase transmission ideas, we show that, for r=3, this channel can achieve strictly greater than K/3 DoF with delayed CSIT. Next, we add the capability of simultaneous transmission and reception, i.e. full-duplex operation, to the transmitters, and investigate its impact on the DoF of the SISO Gaussian K-user interference and M×K X channel under the delayed CSIT assumption. By proposing new cooperation/alignment techniques, we show that the full-duplex transmitter cooperation can potentially yield DoF gains in both channels with delayed CSIT. This is in sharp contrast to the previous results on these channels indicating the inability of full-duplex transmitter cooperation to increase the channel DoF with either perfect instantaneous CSIT or no CSIT. With the recent technological advances in implementation of full-duplex communication, it is expected to play a crucial role in the future wireless systems. Finally, we consider the Gaussian K-user interference and K×K X channel with output feedback, wherein each transmitter causally accesses the output of its paired receiver. First, using the output feedback and under no CSIT assumption, we show that both channels can achieve DoF values greater than one, strictly increasing in K, and approaching the limiting value of 2 as K→∞. Then, we develop transmission schemes for the same channels with both output feedback and delayed CSIT, known as Shannon feedback. Our achievable DoFs with Shannon feedback are greater than those with the output feedback for almost all values of K.

Thesis (Ph.D.); Submitted to the University of California at Berkeley, Berkeley, CA 94720 (US); 1 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "LBNL--56842" Barber IV, John Letherman. USDOE Director. Office of Science. Advanced Scientific Computing Research (US) 12/01/2004. Report is also available in paper and microfiche from NTIS.

Este trabalho contempla o projeto de um manipulador robótico cilindro atuado por motores de passo com cinco juntas de atuação. As etapas do projeto do robô, que tratam este estudo, foram divididas em: projeto mecânico; modelagem matemática; projeto do controlador; e simulações. O projeto mecânico apresenta uma proposta de configuração e dimensionamento mecânicos que supre a demanda exigida para a operação analisada. O modelo matemático apresenta as características elétricas e mecânicas do atuador e as características mecânicas do robô. O projeto de um controlador linear é realizado por meio da alocação dos polos do sistema em malha fechada através da realimentação dos estados de posição e de velocidade angulares do rotor unidos a um integrador do erro de posição angular. Para o primeiro grau de liberdade, por conta da variação do momento de inércia de massa associado a essa junta, um controlador com ganhos parametrizados foi projetado, no qual os ganhos são calculados baseado no modelo matemático relativo ao momento de inércia de massa associado a essa junta. Por meio de simulações computacionais, avaliou-se o projeto dos controladores no movimento ponto a ponto dos cinco eixos de atuação e a variação do momento de inércia de massa sobre a primeira junta. Os resultados dessas simulações mostraram que os controladores propostos cumprem com a dinâmica desejada nos cinco graus de liberdade do robô. / This work contemplates the design of a robotic manipulator, which is operated by a stepper motor with five actuation joints. The robot design steps were divided into: mechanical design; mathematical modeling; controller design; and simulations. The mechanical design presents a proposal of mechanical configuration and sizing that supplies the required demand for the analyzed operation. The mathematical model presents the electrical and mechanical characteristics of the actuator and the mechanical characteristics of the robot. The design of a linear controller is accomplished by allocating the poles of the closed loop system by states feedback of the position and angular speed of the rotor attached to an angular position error integrator. For the first degree of freedom, due to the variation of mass moment of inertia associated with this joint, a controller with parameterized gains was projected, in which the gains are calculated based on the mathematical model related to the mass moment of inertia associated to this joint. By means of computational simulations, we evaluated the design of the controllers in the point-to-point movement of the five actuation joints and the variation of the mass moment of inertia on the first joint. The results of these simulations showed that the proposed controllers comply with the desired dynamics in the robot’s five degrees of freedom.

Este trabalho aborda o projeto de um manipulador robótico cilíndrico acionado pneumaticamente de baixo custo e com 5 graus de liberdade. Este robô está sendo desenvolvido para realizar operações de movimentação de peças que venham a substituir postos de trabalho com ambiente insalubre e/ou de ações repetitivas nas quais as exigências de precisão, velocidade e capacidade de carga sejam limitadas. Os requisitos de projeto foram obtidos por meio de uma pesquisa em uma fábrica de ferramentas manuais. É apresentada a proposta de uma estrutura mecânica para suprir parte significativa das necessidades usuais de movimentação de peças em indústrias manufatureiras e o seu correspondente modelo teórico dinâmico não-linear, considerando o equacionamento dos atuadores pneumáticos acoplados ao sistema mecânico. Finalmente, é apresentado o projeto de um controlador linear por meio da técnica de realimentação de estados, com os ganhos definidos pela alocação de pólos a partir de um modelo linearizado de 3ª ordem. Para validação do modelo teórico e do algorítmo de controle propostos são apresentadas simulações de movimentação ponto a ponto e seguimento de trajetória. Os resultados mostram que a precisão de posicionamento do efetuador final é adequada para as tarefas de manipulação. / This work proposes the design of a low cost cylindrical robotic manipulator actuated pneumatically with 5 degrees of freedom. This robot is being developed to perform manipulation of parts, aiming to replace tasks usually performed in unhealthy environment and/or repetitive actions in which the requirements of accuracy, speed and load capacity are limited. The project requirements were obtained through a research in a manual tools factory. It is proposed a geometry that is intended to meet a significant amount of the usual moving parts demands in manufacturing industries and its corresponding nonlinear dynamic theoretic model, considering the pneumatic actuators model coupled to the mechanical system. Finally, the application of a linear control-law based on the technique of state feedback with design made by pole assignment using a linearized model of 3rd order is described. For validation of the theoretic model and proposed control algorithm are presented simulations of point to point regulation problem and trajectory tracking. The results show that the positioning accuracy of the end effector is suitable for achieving the planned tasks.

xv, 215 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / In this dissertation, several new methods for the measurement and control of transverse photonic degrees of freedom are developed. We demonstrate a mode sorter for two-dimensional (2-D) parity of transverse spatial states of light based on an out-of-plane Sagnac interferometer. The first experimental 2-D parity sorting measurements of Hermite-Gauss transverse spatial modes are presented. Due to the inherent phase stability of this type of interferometer, it provides a promising tool for the manipulation of higher order transverse spatial modes for the purposes of quantum information processing. We propose two such applications: the production of both spatial-mode entangled Bell states and heralded single photons, tailored to cover the entire Poincaré sphere of first-order transverse modes. In addition to the aforementioned transverse spatial manipulation based on free-space parity sorting, we introduce several more such techniques involving photons propagating in optical fibers. We show that when a photon propagates in a cylindrically symmetric waveguide, its spin angular momentum and its orbital angular momentum (OAM) interact. This spin-orbit interaction (SOI) leads to the prediction of several novel rotational effects: the spatial or time evolution of the photonic polarization vector is controlled by its OAM quantum number or, conversely, its spatial wave function is controlled by its spin. We demonstrate how these phenomena can be used to reversibly transfer entanglement between the spin and OAM degrees of freedom of two-particle states. In order to provide a deeper insight into the cause of the SOI for photons, we also investigate an analogous interaction for electrons in a cylindrical waveguide and find that each of the SOI effects mentioned above remain manifest for the electron case. We show that the SOI dynamics are quantitatively described by a single expression applying to both electrons and photons and explain their common origin in terms of a universal geometric phase associated with the interplay between either particle's spin and OAM. This implies that these SOI-based effects occur for any particle with spin and thereby exist independently of whether or not the particle has mass, charge, or magnetic moment. / Committee in charge: Daniel Steck, Chairperson, Physics; Michael Raymer, Member, Physics; Jens Noeckel, Member, Physics; Steven van Enk, Member, Physics; Andrew Marcus, Outside Member, Chemistry

Este trabalho contempla o projeto de um manipulador robótico cilindro atuado por motores de passo com cinco juntas de atuação. As etapas do projeto do robô, que tratam este estudo, foram divididas em: projeto mecânico; modelagem matemática; projeto do controlador; e simulações. O projeto mecânico apresenta uma proposta de configuração e dimensionamento mecânicos que supre a demanda exigida para a operação analisada. O modelo matemático apresenta as características elétricas e mecânicas do atuador e as características mecânicas do robô. O projeto de um controlador linear é realizado por meio da alocação dos polos do sistema em malha fechada através da realimentação dos estados de posição e de velocidade angulares do rotor unidos a um integrador do erro de posição angular. Para o primeiro grau de liberdade, por conta da variação do momento de inércia de massa associado a essa junta, um controlador com ganhos parametrizados foi projetado, no qual os ganhos são calculados baseado no modelo matemático relativo ao momento de inércia de massa associado a essa junta. Por meio de simulações computacionais, avaliou-se o projeto dos controladores no movimento ponto a ponto dos cinco eixos de atuação e a variação do momento de inércia de massa sobre a primeira junta. Os resultados dessas simulações mostraram que os controladores propostos cumprem com a dinâmica desejada nos cinco graus de liberdade do robô. / This work contemplates the design of a robotic manipulator, which is operated by a stepper motor with five actuation joints. The robot design steps were divided into: mechanical design; mathematical modeling; controller design; and simulations. The mechanical design presents a proposal of mechanical configuration and sizing that supplies the required demand for the analyzed operation. The mathematical model presents the electrical and mechanical characteristics of the actuator and the mechanical characteristics of the robot. The design of a linear controller is accomplished by allocating the poles of the closed loop system by states feedback of the position and angular speed of the rotor attached to an angular position error integrator. For the first degree of freedom, due to the variation of mass moment of inertia associated with this joint, a controller with parameterized gains was projected, in which the gains are calculated based on the mathematical model related to the mass moment of inertia associated to this joint. By means of computational simulations, we evaluated the design of the controllers in the point-to-point movement of the five actuation joints and the variation of the mass moment of inertia on the first joint. The results of these simulations showed that the proposed controllers comply with the desired dynamics in the robot’s five degrees of freedom.

Este trabalho aborda o projeto de um manipulador robótico cilíndrico acionado pneumaticamente de baixo custo e com 5 graus de liberdade. Este robô está sendo desenvolvido para realizar operações de movimentação de peças que venham a substituir postos de trabalho com ambiente insalubre e/ou de ações repetitivas nas quais as exigências de precisão, velocidade e capacidade de carga sejam limitadas. Os requisitos de projeto foram obtidos por meio de uma pesquisa em uma fábrica de ferramentas manuais. É apresentada a proposta de uma estrutura mecânica para suprir parte significativa das necessidades usuais de movimentação de peças em indústrias manufatureiras e o seu correspondente modelo teórico dinâmico não-linear, considerando o equacionamento dos atuadores pneumáticos acoplados ao sistema mecânico. Finalmente, é apresentado o projeto de um controlador linear por meio da técnica de realimentação de estados, com os ganhos definidos pela alocação de pólos a partir de um modelo linearizado de 3ª ordem. Para validação do modelo teórico e do algorítmo de controle propostos são apresentadas simulações de movimentação ponto a ponto e seguimento de trajetória. Os resultados mostram que a precisão de posicionamento do efetuador final é adequada para as tarefas de manipulação. / This work proposes the design of a low cost cylindrical robotic manipulator actuated pneumatically with 5 degrees of freedom. This robot is being developed to perform manipulation of parts, aiming to replace tasks usually performed in unhealthy environment and/or repetitive actions in which the requirements of accuracy, speed and load capacity are limited. The project requirements were obtained through a research in a manual tools factory. It is proposed a geometry that is intended to meet a significant amount of the usual moving parts demands in manufacturing industries and its corresponding nonlinear dynamic theoretic model, considering the pneumatic actuators model coupled to the mechanical system. Finally, the application of a linear control-law based on the technique of state feedback with design made by pole assignment using a linearized model of 3rd order is described. For validation of the theoretic model and proposed control algorithm are presented simulations of point to point regulation problem and trajectory tracking. The results show that the positioning accuracy of the end effector is suitable for achieving the planned tasks.