Search results for "MIMO"
showing 10 items of 88 documents
A Trajectory-Driven 3D Non-Stationary mm-Wave MIMO Channel Model for a Single Moving Point Scatterer
2021
This paper proposes a new non-stationary three-dimensional (3D) channel model for a physical millimeter wave (mm-Wave) multiple-input multiple-output (MIMO) channel. This MIMO channel model is driven by the trajectory of a moving point scatterer, which allows us to investigate the impact of a single moving point scatterer on the propagation characteristics in an indoor environment. Starting from the time-variant (TV) channel transfer function, the temporal behavior of the proposed non-stationary channel model has been analyzed by studying the TV micro-Doppler characteristics and the TV mean Doppler shift. The proposed channel model has been validated by measurements performed in an indoor e…
Modelling, analysis, and simulation of mobile-to-mobile MIMO channels
2006
Masteroppgave i informasjons- og kommunikasjonsteknologi 2006 - Høgskolen i Agder, Grimstad The development of mobile communication has been dramatically increasing in recent years. New concepts and methods are necessary for the improvement of existing mobile communication techniques due to the fact of the demand for these systems with higher data rates and a better quality of service. As the number of subscribers is growing rapidly, the development of mobile radio channel models has become one of the most important research topics within mobile communication systems. This thesis deals with a multiple-input multiple-output (MIMO) channel model for mobile- to-mobile communications. It starts…
Modeling the influence of alternative forest management scenarios on wood production and carbon storage: A case study in the Mediterranean region
2016
Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecosystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario …
Control zeros and nonminimum phase LTI mimo systems
1999
Abstract The paper presents a new, general, inverse-model/output-zeroing approach to zeros of LTI discrete-time multivariable, possibly nonsquare systems. It is shown on simple examples that the existing definitions of multivariable zeros fail to detect certain important zeros which contribute to zeroing the system output. As a result, a concept of ‘control zeros’ is introduced, followed by a general redefinition of minimum/nonminimum phase systems, both new contributions being based on the notion of (generalized) inverse systems. Output-zeroing/inverse-model/minimum-variance control-related justifications of the new approach are presented.
Low‐complexity detection for uplink massive MIMO SCMA systems
2020
Paid Open Access UNIT agreement
Low-complexity AoA and AoD estimation in the transformed spatial domain for millimeter wave MIMO channels
2021
La estimación del ángulo de llegada (AoA) y del ángulo de salida (AoD) es fundamental para la búsqueda de celdas, las comunicaciones estables y el posicionamiento en los sistemas celulares de ondas milimétricas (mmWave). Además, el diseño de algoritmos de estimación de AoA/AoD de baja complejidad resulta también de gran importancia en el despliegue de sistemas prácticos para permitir un cálculo rápido y eficiente de la conformación de haz. La estimación paramétrica del canal en ondas milimétricas permite describir la matriz del canal como una combinación de trayectorias de señales dependientes de la dirección, explotando la característica de dispersión de los canales mmWave. En este context…
MODELADO DE UNA PLATAFORMA DE E-MANTENIMIENTO, CMMS Y CBM
2014
The information and communications technologies (ICT) are increasingly used in society and business. ICT have become a key element for business development and the improvement of activities in all departments. Analogously, the rise of Computerized Maintenance Management Systems (CMMS), Condition Based Maintenance (CBM), and the use of remote devices and functions such as e-maintenance, have opened great possibilities for maintenance optimization. Those techniques have resulted in the emergence of technological challenges such as interoperability between different systems in order to exchange and coordinate information. In this context, the application of business process modelling is a cruc…
Antinociceptive and anti-inflammatory activities of Acacia pennata wild (Mimosaceae)
2005
The butanolic fraction of dried leaves of Acacia pennata (Mimosaceae) was tested for analgesic and anti-inflammatory activities in animal models. It showed significant protective effects against chemical stimuli (acetic acid and formalin) in the mouse. It also produced a significant increase of the threshold of sensitivity to pressure-induced pain in the rats. The extract revealed an inhibitory effect in carrageenin-induced rat paw oedema in the late phase. The results suggested that a peripheral mechanism is involved in the analgesic, associated to anti-inflammatory effect (NSAIDs-like). Among the class of compounds characterized in this fraction, flavonoids may be mainly responsible for t…
Estimation of the Velocity of Multiple Moving Persons in Non-Stationary Indoor Environments from Received RF Signals
2019
This paper presents a new accurate iterative procedure to estimate the time-variant (TV) velocity, i.e., TV speed, TV vertical angle-of- motion (VAOM), and TV horizontal angle-of-motion (HAOM), of multiple moving objects/persons in three-dimensional (3D) non-stationary indoor propagation environments. The indoor space is assumed to be equipped with a distributed 3x3 multiple-input multiple-output (MIMO) system. The proposed procedure focuses on estimating the TV speed, TV VAOM, and TV HAOM by matching the spectrogram of the complex channel gain of a non- stationary indoor channel model to the spectrogram obtained from received radio frequency (RF) signals. Together with the velocity …
A New Iterative Estimation Procedure for the Localization of Passive Stationary Objects from Received RF Signals in Indoor Environments
2019
This paper deals with the localization of passive stationary objects from the received radio- frequency (RF) signals in 3-dimensional (3D) indoor environments. Each object located in the 3D indoor environment is modelled by a single point scatterer. The propagation space is equipped with a multiple-input multiple-output (MIMO) wireless communication system. The employed channel model is flexible and allows to have a line-of-sight (LOS) component as well as single- and double- bounce scattering components. Here, we present a new accurate iterative estimation technique for computing the optimal coordinates as well as the number of the main stationary objects (scatterers) in indoor areas. The …