SISO and SIMO indoor wireless transmission systems simulations using the FDTD method (original) (raw)
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Modelling interference for indoor wireless systems using the FDTD method
Antennas and Propagation Society …
A 2D TMz implementation of the Finite-Difference Time-Domain algorithm is used to model radio-wave propagation from multiple transmitter locations in an eight storey building. From the steady-state field data, the Signal-to-Interference Ratio (SIR) is calculated for down-link scenarios. One transmitter is located on each floor and two base-station configurations are examined: aligned and staggered. Vertically-aligned transmitters are found to have better SIR performance -9% of the sectors in the aligned configuration and 23% in the staggered configuration have SIRs less than 5 dB. The central services core significantly reduces the SIR, however this effect can be alleiviated by including another set of vertically-aligned transmitters.
FDTD modeling and characterization of the indoor radio propagation channel in the 434 MHz ISM band
17th International Conference on Applied Electromagnetics and Communications, 2003. ICECom 2003., 2003
In this paper the fundamental aspects of indoor radio propagation are presented and the possibility to characterize a dynamic channel by means of a static model based on the Finite Difference Time Domain method (FDTD) is examined. A 3D office environment is simulated in the 434 MHz ISM band for the characterization of channel operation according to the dominating distortions. The obtained results, which are in agreement with the theoretical values, verify that the channel operation is slow flat fading with No ISI making the application of the spatial diversity the most appropriate scheme.
Numerical Modeling of an Indoor Wireless Environment for the Performance Evaluation of WLAN Systems
2005
A site-specific numerical model, based on the finite-difference time-domain method, is developed in this paper for the indoor radio channel. The scenario of interest is concerned with wave propagation in a typical office environment, for which several simulations are performed considering different placements of the transmitting antenna. Both the 2-and 5-GHz bands are examined, where contemporary wireless local area networks operate. Important channel characteristics are evaluated via the estimation of received power levels, as well as the examination of small-scale fading and time dispersion. Index Terms-Finite-difference time-domain (FDTD) method, indoor propagation, wireless communications.
A hybrid FDTD/UTD radiowave propagation modeling: Application to indoor channel simulations
Microwave and Optical Technology Letters, 2007
Substituting Eqs. 17 and 18 into Eq. , k e and k o can be obtained. Using the following equations, the design parameters s/b and w/b can be obtained: 11. E.H. Fooks and R.A. Zakarevicius, Microwave engineering using microstrip circuits, Prentice Hall, New Jersey, 1990. 12. W. Hilberg, From approximations to exact relations for characteristic impedances, IEEE Trans Microwave Theory Tech MTT-17 (1969), 259 -265. ABSTRACT: Classical theories such as the uniform theory of diffraction use analytical expressions for diffraction coefficients. These methods are convenient for canonical problems and objects much greater than the wavelength and enable to rise in frequency. For more complex and smaller scattering structures, rigorous methods as the finite difference time domain method is more suited. In this article, we present a new look on radiowave propagation prediction, combining the advantages of these two complementary methods. This article presents several studies aiming to evaluate the validity domain of this hybrid method in terms of far-field propagation conditions. Finally, an application to indoor channel modeling is presented. ABSTRACT: In this articel, we have designed, fabricated, and measured a compact rectangular mono-cone antenna for UWB applications. The measured bandwidth is 8.2 GHz from 2.8 GHz to 11 GHz for S 11 Ͻ Ϫ10 dB. The path loss S 11 and phase were measured and discussed. The radiation patterns and antenna gain across the frequency bands are also presented. From the measured results, the proposed antenna shows a good characteristic (almost linear phase, omni-directional pattern, and very low gain variation).
Computational Methods and Experimental Measurements XVII, 2015
Finite Difference Time Domain Method (FDTDM) is a powerful tool to model electromagnetic propagation; once the medium has been defined by its conductivity (, permittivity ( and permeability (, for each position in the computational volume, is possible to "see" the propagation electromagnetic behavior. We have used FDTDM to model waveguides, slot antennas, field effects over different materials and even propagation effects in nanometric spaces. As obstacles produce reflection, refraction and diffraction phenomena, modifying scattering field in free space zones, knowledge of propagation behavior is very useful to define antenna positions and other system characteristics, for WiFi, cellular telephony and other mobile communication systems. We present in this paper, results of EM propagation modeling inside a building, where furniture, structure, walls and any other obstacle has been defined by their EM constants: Modeling shows how EM field is distributed all over the chosen zone, giving an almost exact quantification of field magnitude in each point. Modeling uses Yee algorithm to transform Differential Maxwell Equations into Finite Difference Equations, capable to be handled by the computer program developed by us. The source we used was a 2.4 GHz WiFi access point, allowing us to compare computational results with direct measurements in the experimental area. Each computational point was a 0.6 cm (per side cube, over a zone of 9x4x3 m. Results are presented in both, as images showing field distribution in representative areas of analysis zone, and linear graphics comparing acquired computational and measurement data, showing a no more than 3 dB difference between them.
Statistical characterization and simulation of a femtocell indoor radio channel
2011
This paper presents the statistical analysis of measured propagation data in a femtocell indoor radio environment. Measurements were performed at 1.95 GHz with 160 MHz channel bandwidth. Time domain sounding technique using PN-sequence with a matched filter was employed. Theoretical predictions were also obtained by simulation using the Finite-Difference Time-Domain (FDTD) method, accelerated via GPU technology. Based on experimental and theoretical results, the Saleh-Valenzuela model parameters were obtained, and a comparison between theoretical and experimental results is presented.
Modelling Propagation in Multi-Floor Buildings using the FDTD Method
IEEE TRANSACTIONS ON …, 1900
A three-dimensional parallel implementation of the FDTD method has been used to identify and isolate the dominant propagation mechanisms in a multi-storey building at 1.0 GHz. A novel method to visualise energy flow by computing streamlines of the Poynting vector has been developed and used to determine the dominant propagation mechanisms within the building. It is found that the propagation mechanisms depend on the level of internal clutter modelled. Including metallic and lossy dielectric clutter in the environment increases attenuation on some propagation paths, thereby altering the dominant mechanisms observed. This causes increases in the sector-averaged path-loss and changes the distance-dependency exponents across a floor from 2.2 to 2.7. The clutter also reduces Rician K-factors across the floor. Directly comparing sector-averaged path-loss from the FDTD simulations with experimental measurements shows an RMS error of 14.4 dB when clutter is ignored. However, this is reduced to 10.5 dB when the clutter is included, suggesting that the effects of clutter should not be neglected when modelling propagation indoors.
IEEE Transactions on Antennas and Propagation, 2004
An accurate uniform theory of diffraction (UTD) model for the analysis of complex indoor radio environments, in which microwave WLAN systems operate, is presented. The model employs a heuristic UTD coefficient suitable to take into account the effects of building floors, walls, windows, and the presence of metallic and penetrable furniture. A numerical tool based on an enhanced tridimensional beam-tracing algorithm, which includes diffraction phenomena, has been developed to compute the field distribution with a high degree of accuracy. After the validation of the model, obtained by means of some comparisons with measurements available in literature, an accurate electromagnetic characterization of typical indoor environments has been performed. The numerical results show that the electromagnetic field distribution and the channel performances are significantly influenced by the diffraction processes arising from the presence of furniture.