Receive Spatial Modulation for Massive MIMO Systems

In this paper, we consider the downlink of a massive multiple-input-multiple-output (MIMO) single user transmission system operating in the millimeter wave outdoor narrowband channel environment. We propose a novel receive spatial modulation architecture aimed to reduce the power consumption at the user terminal, while attaining a significant throughput. The energy consumption reduction is obtained through the use of analog devices (amplitude detector), which reduces the number of radio frequency chains and analog-to-digital-converters (ADCs). The base station transmits spatial and modulation symbols per channel use. We show that the optimal spatial symbol detector is a threshold detector that can be implemented by using one bit ADC. We derive closed form expressions for the detection threshold at different signal-to-noise-ratio (SNR) regions showing that a simple threshold can be obtained at high SNR and its performance approaches the exact threshold. We derive expressions for the average bit error probability in the presence and absence of the threshold estimation error showing that a small number of pilot symbols is needed. A performance comparison is done between the proposed system and fully digital MIMO showing that a suitable constellation selection can reduce the performance gap

Energy-Efficient Architecture for Receive Spatial Modulation in Large MIMO Systems

Cost and power consumption are substantial challenges for multiple-input-multiple-output (MIMO) wireless communication systems when the number of antennas and the operating carrier frequency increase. We present a low cost and low power consumption receive spatial modulation (RSM) architecture based on a simple receiver design. We propose a time-division-duplex (TDD) transmission protocol aimed to reduce the training overhead where the channel knowledge is required only at the base station. Simulation results presented show that the power consumption and the energy efficiency of the proposed RSM architecture outperform the hybrid and conventional MIMO systems

Application of Treated Oil Sands Drill Cuttings Waste in Micropiles Construction

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout mixtures used for micropiles construction. In this study, the physical, chemical and mineralogical characteristics of the treated oil sands drill cuttings waste were investigated. Fresh and hardened properties for micropiles grouts incorporating the treated solid drill cuttings waste were evaluated. Moreover, the effects of employing these grout mixtures on micropiles cross-section, surface interface properties and axial behaviour were investigated. The results showed that incorporating up to 20% of the treated solid drill cuttings waste as a partially replacement of cement will not adversely affect the properties of the grout. On the other hand, leaching tests evidenced the reduction in the release of heavy metals from the tested mixtures compared to that of the raw waste indicating successful stabilization/solidification of such waste in the grout. In addition, it was noticed an enhancement in the grout body diameter for micropiles installed using the developed grout, while maintaining the micropile surface properties. Moreover, micropiles installed using grout incorporating a high percentage of the TOSW (up to 30%) exhibited the same axial behaviour as that of micropile installed using conventional grout. Therefore, incorporating TOSW in micropile applications has high potential for producing cost efficient micropiles along with providing a green oil sands waste management solution

Spatial modulation schemes and modem architectures for millimeter wave radio systems

The rapid growth of wireless industry opens the door to several use cases such as internet of things and device-to-device communications, which require boosting the reliability and the spectral efficiency of the wireless access network, while reducing the energy consumption at the terminals. The vast spectrum available in millimeter-wave (mmWave) frequency band is one of the most promising candidates to achieve high-speed communications. However, the propagation of the radio signals at high carrier frequencies suffers from severe path-loss which reduces the coverage area. Fortunately, the small wavelengths of the mmWave signals allow packing a large number of antennas not only at the base station (BS) but also at the user terminal (UT). These massive antenna arrays can be exploited to attain high beamforming and combining gains and overcome the path-loss associated with the mmWave propagation. In conventional (fully digital) multiple-input-multiple-output (MIMO) transceivers, each antenna is connected to a specific radio-frequency (RF) chain and high resolution analog-to-digital-converter. Unfortunately, these devices are expensive and power hungry especially at mmWave frequency band and when operating in large bandwidths. Having this in mind, several MIMO transceiver architectures have been proposed with the purpose of reducing the hardware cost and the energy consumption. Fully connected hybrid analog and digital precoding schemes were proposed in with the aim of replacing some of the conventional RF chains by energy efficient analog devices. These fully connected mapping requires many analog devices that leads to non-negligible energy consumption. Partially connected hybrid architectures have been proposed to improve the energy efficiency of the fully connected transceivers by reducing the number of analog devices. Simplifying the transceiver’s architecture to reduce the power consumption results in a degradation of the attained spectral efficiency. In this PhD dissertation, we propose novel modulation schemes and massive MIMO transceiver design to combat the challenges at the mmWave cellular systems. The structure of the doctoral manuscript can be expressed as In Chapter 1, we introduce the transceiver design challenges at mmWave cellular communications. Then, we illustrate several state of the art architectures and highlight their limitations. After that, we propose scheme that attains high-energy efficiency and spectrum efficiency. In chapter 2, first, we mathematically describe the state of the art of the SM and highlight the main challenges with these schemes when applied at mmWave frequency band. In order to combat these challenges (for example, high cost and high power consumption), we propose novel SM schemes specifically designed for mmWave massive MIMO systems. After that, we explain how these schemes can be exploited in attaining energy efficient UT architecture. Finally, we present the channel model, systems assumptions and the transceiver devices power consumption models. In chapter 3, we consider single user SM system. First, we propose downlink (DL) receive SM (RSM) scheme where the UT can be implemented with single or multiple radio-frequency chains and the BS can be fully digital or hybrid architecture. Moreover, we consider different precoders at the BS and propose low complexity and efficient antenna selection schemes for narrowband and wideband transmissions. After that, we propose joint uplink-downlink SM scheme where we consider RSM in the DL and transmit SM (TSM) in the UL based on energy efficient hybrid UT architecture. In chapter 4, we extend the SM system to the multi-user case. Specifically, we develop joint multi-user power allocation, user selection and antenna selection algorithms for the broadcast and the multiple access channels. Chapter 5 is presented for concluding the thesis and proposing future research directions.Considerando los altos requerimientos de los servicios de nueva generación, las infraestructuras de red actual se han visto obligadas a evolucionar en la forma de manejar los diferentes recursos de red y computación. Con este fin, nuevas tecnologías han surgido para soportar las funcionalidades necesarias para esta evolución, significando también un gran cambio de paradigma en el diseño de arquitecturas para la futura implementación de redes.En este sentido, este documento de tesis doctoral presenta un análisis sobre estas tecnologías, enfocado en el caso de redes inter/intra Data Centre. Por consiguiente, la introducción de tecnologías basadas en redes ópticas ha sido estudiada, con el fin de identificar problemas actuales que puedan llegar a ser solucionados mediante el diseño y aplicación de nuevas técnicas, asimismo como a través del desarrollo o la extensión de los componentes de arquitectura de red.Con este propósito, se han definido una serie de propuestas relacionadas con aspectos cruciales, así como el control de dispositivos ópticos por SDN para habilitar el manejo de redes híbridas, la necesidad de definir un mecanismo de descubrimiento de topologías ópticas capaz de exponer información precisa, y el analizar las brechas existentes para la definición de una arquitectura común en fin de soportar las comunicaciones 5G.Para validar estas propuestas, se han presentado una serie de validaciones experimentales por medio de escenarios de prueba específicos, demostrando los avances en control, orquestación, virtualización y manejo de recursos con el fin de optimizar su utilización. Los resultados expuestos, además de corroborar la correcta operación de los métodos y componentes propuestos, abre el camino hacia nuevas formas de adaptar los actuales despliegues de red respecto a los desafíos definidos en el inicio de una nueva era de las telecomunicaciones.Postprint (published version

人間とロボット間の知的協調に関する研究

博士(工学)大阪市立大

Results of arthroscopic treatment of femroacetabular impingement (FAI)

Introduction: Femoroacetabular impingement (FAI) has been suggested as an important etiology of pain in the groin region in young adults especially athletes and there are theories connecting it to early onset osteoarthritis.Aim: To assess the results of arthroscopic treatment of FAI.Patients: Forty patients had been managed arthroscopically for their FAI in both El-Hadra university hospital and William Harvey Hospital.Methods: Results of arthroscopic treatment of FAI in 40 consecutive patients had been evaluated using patients reported outcomes (modified Harris Hip Score and international Hip Outcome Tool-12) and clinical measures of improvement of range of motion in both flexion and internal rotation in 90o of hip flexion.Results: The average of the outcome scores showed statistically significant improvement following the arthroscopic intervention.Conclusion: Femroacetabular impingement is an important etiology of groin pain in young adults, nevertheless the athletes. Diagnosis of this condition is primarily a clinical one to be supported with relevant imaging. Hip arthroscopy is an effective approach to treat and correct the underlying bony abnormalities of FAI. Younger age of patients predicts better improvement in i-HOT-12 score.Keywords: Hip, Arthroscopy, FAI, Labral tear, Cam lesion, Labral repair, MR

Optimization of energy consumption in cloud computing datacenters

Cloud computing has emerged as a practical paradigm for providing IT resources, infrastructure and services. This has led to the establishment of datacenters that have substantial energy demands for their operation. This work investigates the optimization of energy consumption in cloud datacenter using energy efficient allocation of tasks to resources. The work seeks to develop formal optimization models that minimize the energy consumption of computational resources and evaluates the use of existing optimization solvers in testing these models. Integer linear programming (ILP) techniques are used to model the scheduling problem. The objective is to minimize the total power consumed by the active and idle cores of the servers’ CPUs while meeting a set of constraints. Next, we use these models to carry out a detailed performance comparison between a selected set of Generic ILP and 0-1 Boolean satisfiability based solvers in solving the ILP formulations. Simulation results indicate that in some cases the developed models have saved up to 38% in energy consumption when compared to common techniques such as round robin. Furthermore, results also showed that generic ILP solvers had superior performance when compared to SAT-based ILP solvers especially as the number of tasks and resources grow in size

Development of a multi-purpose proton microbeam system: irradiation of tumor cells by energetic protons at the Bragg peak

Employing ionization radiation to serve our communities has various applications in agricultural, industrial, and medical fields. The application of physics to medicine deals mainly with ionizing radiation in diagnosis and treating human therapeutic. Radiation treatment is a commonly utilized treatment for a variety of cancers in humans. The aim of utilizing radiation is to destroy tumor cells while reducing damage to healthy cells, and new techniques that can achieve that purpose are continuously being developed. A charged particle microbeam is a specialized opportunity to precisely control the number of particles crossing the individual cells and the dose location within the cell. The design and construction of the collimation and detection system significantly impact the target accuracy. At East Carolina University, a horizontal multi-purpose microbeam and broad-beam system have been developed with a single electrostatic quadrupole quadruplet focusing lens. It has been combined with the 2 MV tandem Pelletron accelerator to generate a micrometer-sized beam and broad-sized beam for cell irradiation research. This system will have the capability to be used as the primary beam for a microPIXE (particle-induced x-ray emission) and neutron microbeam experimental system. In this study, an electrostatic quadruplet lens and a 10 µm Havar exit window were used to generate a proton microbeam, measured using the knife-edge technique. A 3 MeV proton beam was used to irradiate MCF 7 cancer cells at 0.5 and 1 Gy doses. In conjunction with these doses, the survival curve was calculated using the PrestoBlue assay