Impact of a Concrete Room on the Performance of Cellular Telephone Communications for Low Bit Rate Applications (original) (raw)
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Characterisation of the Indoor Mobile channel using a Ray Tracing Model
2007
A ray tracing model is constructed to investigate the propagation mechanisms underlying indoor radio communications. The model is used as the basis for a simulation of two buildings for which measured data is available. Characteristics of the channel distributions are determined using the simulation, and the role of di raction in indoor propagation is also demonstrated.
A Propagation Model of Cellular Mobile Radio Communication in Urban Areas
A numerical modeling of the propagation path loss using Uniform Theory of Diffraction (UTD) has been presented here. Computed results at 835 MHZ have been presented for various parameters of interest. The results at 2.154GHz have been obtained and compared with that of Walfish and Bertoni [1]. These are found to be in excellent agreement thereby establishing the validity of the code. Method is simple, efficient and reliable. Both shadow zone and line of sight zone have been considered.
Characterisation of the indoor mobile radio channel using a ray tracing technique
1992 IEEE International Conference on Selected Topics in Wireless Communications, 1992
Investigation of the mechanisms of radio propagation in the indoor environment can only be performed using a detailed simulation of the environment. To this end, a model of the environment has been developed using ray tracing techniques. The model inherently incorporates the near-eld e ects of multipath environment where the transmitter and receiver are in close proximity. Statistical analysis of the resulting model has shown that an adequate match between the real environment and the simulation can be achieved. A Nakagami model is found to describe the fast fading component of the channel well.
The use of Ray Tracing in Characterising the Indoor Mobile Radio Channel
2007
This paper presents a technique of modelling the indoor radio channel that provides an insight into the propagation mechanisms involved. The model by its nature provides a detailed account of the channel, with access to all of the system parameters. To demonstrate the validity of this model, results are presented which show the close match between the real environment and the simulated environment. Although gross approximations are made about the environment, the model still gives good results, highlighting the important parameters that need to be considered in channel models.
Advances in Science, Technology and Engineering Systems Journal, 2018
The main target of this article is to study the provision of indoor service (coverage) using outdoor base station at higher frequencies i.e. 10 GHz, 30 GHz and 60 GHz. In an outdoor to indoor propagation, an angular wall loss model is used in the General Building Penetration (GBP) model for estimating the additional loss at the intercept point of the building exterior wall. A novel angular wall loss model based on a separate incidence angle in azimuth and elevation plane is proposed in this paper. In the second part of this study, an Extended Building Penetration (EBP) model is proposed, and the performance of EBP model is compared with the GBP model. In EBP model, the additional fifth path known as the "Direct path" is proposed to be included in the GBP model. Based on the evaluation results, the impact of the direct path is found significant for the indoor users having the same or closed by height as that of the height of the transmitter. For the indoor users located far away from the exterior wall of building, a modified and enhanced approach of ray tracing type is proposed in this article. In the light of acquired simulation results, the impact of a modified ray tracing approach is emphasized.
Propagation modelling for indoor wireless communication
Electronics & Communication Engineering Journal, 1995
It is important to characterise the indoor radio propagation channel to ensure satisfactory performance of a wireless communication system. Site measurements can be costly; propagation models have been developed as a suitable low-cost alternative. The existing models can be classified into two major classes: statistical models and site-specific propagation models. Statistical models rely on measurement data; site-specific propagation models are based on electromagnetic-wave propagation theory. The ray-tracing technique is very useful in site-specific propagation modelling. This paper gives an overview of indoor propagation modelling and concentrates on a discussion of the raytracing modelling technique because of its practical appeal and its applicability t o any environment.
A deterministic model for spherical wave propagation in microcellular urban environment is presented. This method is based on ray tracing and uniform theory of diffraction. The various ray contributions includes the diffraction from corner of obstacle, reflection from ground and direct wave. According to the height of transmitting station, different ray paths will be presented in the received signal. Calculation is carried out using hard and soft polarization. Results can be used for the planning of new cellular system.
Radio-propagation model based on the combined method of ray tracing and diffraction
IEEE Transactions on Antennas and Propagation, 2006
In this paper, we consider UHF radio wave propagation in vegetated residential environments. The attenuating effects of trees as well as those due to diffraction over the buildings are investigated. A new radio wave propagation prediction model based on the combined method of ray tracing and diffraction (CMRTD) is proposed. A row of trees is modeled as a two-dimensional (2-D) cylinder. It is then represented by an equivalent phase object (EPO); a row of buildings is replaced by an absorbing screen. The position and size of the EPO as well as the amplitude and phase distributions of the input field at the EPO are determined by ray tracing. Next the scattered field is computed by the Kirchhoff diffraction theory. Among the numerical results are those of the scattering from a row of trees with circular or elliptic canopies and the scattering from a row of trees/buildings configuration. The calculations treat both plane-and cylindrical-incident waves. By comparing the results with those obtained from the exact eigenfunction expansion method, we show that the CMRTD is an accurate and efficient method to calculate the scattering from a 2-D cylinder. Moreover, the range of the validity of using the CMRTD to model the scattering from one row of trees is determined.
The fundamental sculpt of radio waves propagation is the radiation of radio waves from a point-source electromagnetic energy to different directions. In practice, this radiated energy varies and diminishes in strength as it propagates from the point-source to the receiver. The level of attenuation of this radio wave can be determined by many factors. Researchers on urban wireless microcells networks, had very often, focused on measurements and modeling of reflected and diffracted rays from corners of structures and their exterior walls. In some cases the structures in questions were treated as opaque to signal propagating under terrestrial mobile frequency range. The attenuation capacity of these structures forms the basis of this study. Quasi-two-dimensional ray-based model was employed during the study. The transmitting and receiving antennae heights were erected at elevation levels not above the top of an average roof, while the base station antenna was assumed to be at the same height as the mobile station to enable the transmitted rays to propagate in a horizontal plane. This was anchored on the theory that transmitted e-m waves have uniform distribution as it propagated through different layers of the building. The attenuation coefficients of other obstructions in the periphery of the environment were not considered. Furthermore, only the exterior building coordinates were assumed to be known. X (τ) = , which has a pulse-like shape, to estimate the complex impulse response (CIR) of the channel under examination. According to the transmission mode of the building penetration model, the building transmission loss was given as: L t = b d m-20log|T (r 1)|-20log|T (r 2)| dB The attenuation factors, b for this study was higher than the specific attenuation factors evaluated for 2GHz, signal penetration for buildings. The values ranged between 0.3dB/m and 0.6dB/m, while propagation loss ranged from 20 dB to 40 dB. Previous research works have posted values more than 40dB. The variance observed here can be attributed to how dense the urban location is, and the focus on high rain forest zone in the Niger Delta region of Nigeria. The study shall be very useful during the planning stages of microcellular networks, routing configuration-guide and network performance management. The limitation of the study is the inability to determine the attenuation coefficient per building.
IEEE Transactions on Vehicular Technology, 2000
In this paper, a ray-tracing technique to predict the propagation channel parameters in indoor scenarios is presented. It is a deterministic technique, fully three-dimensional, based on geometrical optics (GO) and the uniform theory of diffraction (UTD). A model of plane facets is used for the geometrical description of the environment. The ray tracing is accelerated considerably by using the Angular Z-Buffer algorithm. Some comparisons between predicted results and measurements are presented to validate the method. degrees in telecommunications engineering from the Polytechnic University of Madrid (UPM), Spain, in 1977 and 1982, respectively. From 1976, he was with the Radiocommunication and Signal Processing Department, UPM, teaching and doing research. He was a Professor at the University of Cantabria from 1989 to 1998. He is currently a Professor at the University of Alcalá, Madrid. He has worked on about 25 research projects solving problems of electromagnetic compatibility in radio and telecommunication equipment, antennas, microwave components, and radar cross section and mobile communications. He has developed and applied CAD tools for radio-equipment systems such as navy ships, aircraft, helicopters, and satellites, the main contractors being Spanish or European Institutions such as CASA, ALCATEL, DASA, SAAB, INTA, BAZAN, the Spanish Defense Department, and the French company MATRA. He is working now on projects for Telefonica (the largest Spanish telecommunication company) to develop computer tools for propagation analyses in microcells and indoor cells. He has directed about a dozen Ph.D. dissertations; has published about 35 papers, two books, and about ten book chapters; has given short courses; and has given around 100 presentations in international symposia.