Correlation Analysis between Multi-Sources in Indoor Corridors and Tunnels (original) (raw)

Analysis of electromagnetic wave propagation in indoor environments

2012

The wireless networks have been the object of many studies and analyzes of current technology industry, providing not only communication with mobility to end users, but also incorporating new applications. One such technology is known as Wireless Fidelity (Wi-Fi) 802.11. This paper aims to present the behavior of the propagation of electromagnetic waves radiated from an access point Wi-Fi (AP), with different positions of the antenna. These analyses were based on measurements taken in an environment considering line of sight (LOS) at different distances from the AP, but in a confined environment. Consequently, although there were no obstacles (LOS) between transmitter and receiver, there were conditions of confinement on the propagated signal, given the characteristics of this environment (such as the height of the ceiling and the walls themselves). Thus, measurements were made by switching the antenna positioning of the access point, vertically and horizontally. From the analysis of these measurements, it was possible to verify the positioning of the antenna in the access point that generated improved signal coverage, even moderately. In addition, from the measured data (statistically based) the technique of linear regression was used in order to generate mathematical models for each specific situation measured. These proposed models were compared to the Friis model plus correction factors, and were used both for validating the measurements, as a basis for installation of new access points in similar environments.

UHF Propagation in Indoor Hallways

IEEE Transactions on Wireless Communications, 2004

A new model for UHF propagation in large buildings is presented. This model relies on knowledge of the interior arrangement of the building without requiring much detail. The guiding of radiation along hallways is the most significant propagation process at distances of more than 10 m from the transmitter. The waveguide model predicts the power loss rate along the hallways, which is affected by the coupling among the propagating modes. The coupling results from the roughness of the surfaces in the building; it is predicted in an average manner using the average deviation of the walls from perfect smoothness. © axis. The lower order modes are decomposed into plane waves that propagate in an almost parallel direction to the © axis. High order modes travel in directions increasingly oblique to the ©

Indoor Wave Propagation Prediction for Corridors Segments with Partially Reflecting Walls by Using 3D Waveguide Modal Analysis

2016

In this paper, a model is presented to simulate wave propagation in indoor corridors with partially reflecting walls. The model is based on combination of modal analysis, dyadic Green's function, mode matching method and generalized scattering matrix. A new approach to simulate the effect of partial reflectivity of the walls of the waveguide model is proposed. This approach is based on approximating the fields inside the space of the actual waveguide section by equivalent waveguide sections of larger dimensions with PEC (Perfect Electric Conductor) walls. A simple scenario is considered in order to check the accuracy of this model. This scenario is verified by comparing experimental and numerical simulation results. The obtained results show that the proposed model is suitable for predicting accurate electric field strength due to an electromagnetic source in an indoor environment with partially reflecting boundaries.

An Investigation on the Effects of Wall Parameters on the Indoor Wireless Propagations

2007 5th Student Conference on Research and Development, 2007

The type of the construction materials of the interior walls of the indoor environments plays a great role in the propagation of the transmitted signals inside the buildings. A comparison of calculated and simulated Fresnel reflection and transmitted coefficients at 2.4 GHz and 900 MHz for a variety of typical exterior building surfaces has been achieved. The effect of the different types of wall on the path loss prediction had been conducted by using a ray tracing program with real time reflection and refraction phenomena.

A Survey of Radio Propagation Modeling for Tunnels

—Radio signal propagation modeling plays an important role in designing wireless communication systems. The propagation models are used to calculate the number and position of base stations and predict the radio coverage. Different models have been developed to predict radio propagation behavior for wireless communication systems in different operating environments. In this paper we shall limit our discussion to the latest achievements in radio propagation modeling related to tunnels. The main modeling approaches used for propagation in tunnels are reviewed, namely, numerical methods for solving Maxwell equations, waveguide or modal approach, ray tracing based methods and two-slope path loss modeling. They are discussed in terms of modeling complexity and required information on the environment including tunnel geometry and electric as well as magnetic properties of walls.

On the Importance of the MIMO Channel Correlation in Underground Railway Tunnels

Journal of Communications, 2009

This paper deals with MIMO channel modeling according to the correlation level in underground railway tunnels for various antenna configurations for the transmitting and receiving arrays. MIMO channel matrices have been computed with a 3D ray-tracing based software at 2.4 GHz and 5.8 GHz in two different tunnel environments: 1) a 1-track empty tunnel with a square cross section, 2) a 1-track tunnel with a square cross section in which a train is parked between the transmitter and the receiver. In this paper, two different strategies are investigated to model the MIMO channel using the Kronecker and the Weichselberger correlation based channel models. The first one is to model the MIMO channel using a single model over the total tunnel length. The second one takes into account the correlation at the receiving side according to the transmitter-receiver distance. In the latter solution, it is possible to isolate specific areas in the tunnel with specific correlation properties and model them in an independent way to take them into account in a system simulation. In this paper, these two modeling strategies are compared in terms of channel capacity.

Investigation of indoor propagation of WLAN signals

Indonesian Journal of Electrical Engineering and Computer Science

The propagation of radio waves inside a typical university building is investigated by simulation and measurements. The Line of sight (LOS) and Obstructed Line of sight (OLOS) propagation scenarios were considered. The received power from a WLAN access point operating at 2.45GHz was determined from the simulations and measurements at various positions, orientations, and heights of the Tx and Rx antennas. The path loss exponents were estimated from the obtained simulation and measurement results of the received power variation with distance. The obtained path loss exponent values were found between 1.15-1.63 for LOS propagation and 2.14-2.55 for OLOS.

MIMO propagation channel characteristics in tunnels

This paper deals with MIMO channels modeling in tunnels. A full 3D ray-tracing based simulator is used to simulate the MIMO channel in a 1-track tunnel for various antennas configurations at the transmitter and at the receiver. A parametric study is described. The main purpose consists in determining correlation based MIMO channel statistical models and evaluating their performances in an empty tunnel. Channel models obtained with the Kronecker and the Weichselberger models are compared in terms of envelope of the matrix coefficients distribution and mean channel capacity. The best configurations which model correctly the channel while maximizing its capacity will be given.