Search results for "MIMO"

A New Iterative Procedure for the Localization of a Moving Object/Person in Indoor Areas from Received RF Signals

2019

This paper presents a new iterative estimation method to localize a single moving object or person in non-stationary 3-dimensional (3D) indoor environments from received radiofrequency (RF) signals. The moving object/person is modelled by a moving single point scatterer. The indoor space is equipped with a multiple-input multiple-output (MIMO) communication system. This work starts by introducing a new geometrical channel model which considers the effects of the line-of-sight (LOS) component, the fixed objects located in a room, and the moving object (point scatterer). Then, we present an iterative estimation technique for computing the time-variant (TV) coordinates of the moving scatterer.…

Constrained minimum variance control of nonsquare LTI MIMO systems

2010

Constrained minimum variance control is offered for nonsquare LTI MIMO systems. A constrained control design takes advantage of the so-called control zeros. The new control strategy is compared with familiar generalized minimum variance control and possible application areas of the two are discussed.

Stationarity Test for Wireless Communication Channels

2009

In this article, we propose a new test to determine the intervals of stationarity for wireless communication channels. The intervals of stationarity are identified by comparing the delay power spectral density (PSD) estimated at different time instances. The performance of the proposed stationarity test has been evaluated based on the synthetic data generated using a channel simulator. The analysis of the stationarity intervals for two radio communication channels measured in different propagation scenarios reveals that the number and the length of the stationarity intervals decrease as the dimensions of the channel matrix increase.

MIMO Channel Models

2011

Pursaethosides A-E, triterpene saponins from Entada pursaetha.

2005

Five new triterpenoid saponins, pursaethosides A-E (1-5), were isolated from the n-BuOH extract of the seed kernels of Entada pursaetha along with the known phaseoloidin. The structures of 1-5 were elucidated mainly by spectroscopic data interpretation and chemical degradation. Pursaethosides C-E (3-5) possess as a common structural feature entagenic acid as aglycon, which is rare among triterpene saponins. Compounds 2-4 and phaesolidin were found to be not cytotoxic when tested against HCT 116 and HT-29 human colon cancer cells.

Mobile radio channel models for present and future wireless communication systems

2008

From the beginnings of mobile communication, there is a high demand for realistic models for mobile fading channels. The reason for the demand is that channel models are essential for the performance evaluation, parameter optimisation, and test of mobile communication systems. Design methods for mobile fading channels are therefore of great importance for system engineers who are involved in the development of present and future mobile communication systems. In this presentation, an overview will be given about several design methodologies commonly used for the design of mobile radio channel models in present and future wireless communication systems. All presented channel models have in co…

A wideband multiple-cluster MIMO mobile-to-mobile channel model based on the geometrical street model

2008

In this paper, we extend the geometrical street multiple-input multiple-output (MIMO) mobile-to-mobile (M2M) channel model with respect to multiple clusters of scatterers as well as to frequency selectivity. The statistical properties of the proposed reference model are studied. Analytical solutions are provided for the three-dimensional (3D) space-time cross-correlation function (CCF), the temporal autocorrelation function (ACF), the 2D space CCF, and the frequency correlation function (FCF). The correlation properties are studied under the assumption of non-isotropic scattering conditions. The proposed reference model can be used as a starting point for the derivation of a wideband MIMO M…

Posets That Locally Resemble Distributive Lattices

2000

Abstract Let P be a graded poset with 0 and 1 and rank at least 3. Assume that every rank 3 interval is a distributive lattice and that, for every interval of rank at least 4, the interval minus its endpoints is connected. It is shown that P is a distributive lattice, thus resolving an issue raised by Stanley. Similar theorems are proven for semimodular, modular, and complemented modular lattices. As a corollary, a theorem of Stanley for Boolean lattices is obtained, as well as a theorem of Grabiner (conjectured by Stanley) for products of chains. Applications to incidence geometry and connections with the theory of buildings are discussed.

A narrowband MIMO car-to-car channel model based on the geometrical street scattering model

2012

In this paper, we model a narrowband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed channel model, an infinite number of scatterers are uniformly distributed in rectangular grids located on both sides of the street. Analytical solutions are presented for the three-dimensional (3D) space-time cross-correlation function (CCF), the temporal autocorrelation function (ACF), and the two-dimensional (2D) space CCF. An …

Designing Precoding and Receive Matrices for Interference Alignment in MIMO Interference Channels

2017

Interference is a key bottleneck in wireless communication systems. Interference alignment is a management technique that align interference from other transmitters in the least possibly dimension subspace at each receiver and provides the remaining dimensions for free interference signal. An uncoordinated interference is an example of interference which cannot be aligned coordinately with interference from coordinated part; consequently, the performance of interference alignment approaches are degraded. In this paper, we propose a rank minimization method to enhance the performance of interference alignment in the presence of uncoordinated interference sources. Firstly, to obtain higher mu…