Review of in-building propagation phenomena at UHF frequencies (original) (raw)

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 ©

Characteristics of the indoor propagation channel in 1.9 GHz band

This paper presents results of propagation measurements carried out in the frequency range 1 8 2 0 1 8 2 0 1 8 2 0 GHz inside a building, using network analyser. Wideband properties of the channel, described through mean delay and delay spread, and a narrowband local statistics of the received power have been presented. For each transmitter and receiver antennas location two propagation cases have been considered, line of sight (LOS) and obstructed line of sight (NLOS) -the direct path component was attenuated by radio absorbing mat near the receiver.

In-Building Radio Propagation at 900 MHZ in Multi Storied Building

International Journal of Distributed and Parallel systems, 2011

The proliferation of PCS has necessitated the complete characterization of radio channels existing inside buildings. The indoor radio channel differs from the conventional mobile radio channel in two aspects. First of all the distances taken in account are a lot small, and then the inconsistency of the environment is much larger for a smaller range of distance between transmitter and receiver. Indoor use of wireless systems poses one of the major design challenges, as indoor radio (RF) propagation is essentially a complex phenomenon. In this paper we will try to emphasis on this odd subject and will try to compute and place boundaries for use of wireless systems within buildings at 900 MHz. There are many good system design tools which have been developed solely for ground mobile cellular systems. However, no proper design tools have been developed for both ground mobile communication and in-building communications operated within one cellular system. As cellular systems are operated today, in-building communication is provided by transmitting radio signals from cell sites so that they penetrate the building walls to reach portable handsets inside buildings. In-building communication is harder to perform on the reverse link (portable-to-base link) than the forward link. Du to this it is difficult to mathematically put the model for all telecommunication systems in a single equation so many models coexist for different types of radio links for different situations. In this paper statically modelled is been explored.. The model rely on computing the median path loss for a link under a certain probability that the considered conditions will occur The modelling is done using simple measurements made especially for an intended communication system or spectrum allocation. This paper present radio signal propagation measurement and modelling at 900MHz, within a Hotel building in the city of Udaipur (India).

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.

Indoor environment propagation review

Computer Science Review, 2020

A survey of indoor propagation characteristics is presented, including different models for path loss, shadowing and fast fading mechanisms, different channel parameters including signal strength, power delay, coherence bandwidth, Doppler spread and angle of arrival. The concepts of MIMO channels are also covered. The study also explores many types of deterministic channel modelling, such as Finite Difference Time Domain, Finite Integration Method, Ray tracing and the Dominant path model. Electromagnetic properties of building materials, including frequency dependence, are also investigated and several models for propagation through buildings are reviewed.

Wideband Propagation Channel Parameters Measurement Inside an University Building

Contemporary communications are predominantly wireless. Wireless systems propagation parameters are greatly influenced by multipath fading, even more so in an “indoor” environment. Theoretical parameters commonly used for describing multipath are coherence bandwidth and multipath delay spread. The goal of this paper is presentation of results of impulse response measurements in 2.4-GHz frequency band, conducted inside FESB building, using vector analyzer method. From the obtained channel impulse response delay spread was calculated, and the estimate of coherence bandwidth was made. Measurements were divided in four sets, each showing fair correlation of coherence bandwidth and delay spread results.

Measurements and modeling of temporal variations of the indoor radio propagation channel

IEEE Transactions on Vehicular Technology, 1994

This paper reports the results of extensive measurements and analysis of the indoor radio propagation channel's temporal variations. The empirical data base consists of 192 one-min recordings of CW envelope fading waveforms with both antennas stationary. Measurements were carried out in an office environment at 1100 MHz with four transmitter-receiver antenna separations of 5,10,20, and 30 m. Effects of controlled degrees of motion with 0, 1, 2, 3, or 4 individuals walking around the high antenna only, around the low antenna only, and around both antennas were investigated. The reported results include amplitude fading distributions, correlation properties, level crossing rates, duration of fades statistics, and spectrum widths of the frequency domain data. The results can be used in fixed wireless computer communication applications, and in supplementing the available spatial variation models of the indoor radio propagation channel.

A theoretical model of UHF propagation in urban environments

IEEE Transactions on Antennas and Propagation, 2000

Urban communications systems in the UHF band, such as cellular mobile radio, depend on propagation between an elevated antenna and antennas located at street level. While extensive measurements of path loss have been reported, no theoretical model has been developed that explains the effect of buildings on the propagation. The development of such a model is given in which the rows or blocks of buildings are viewed as diffracting cylinders lying on the earth. Representing the buildings as absorbing screens, the propagation process reduces to multiple forward diffraction past a series of screens. Numerical computation of the diffraction effect yields a power law dependence for the field that is within the measured range. Accounting for diffraction down to street level from the rooftops gives an overall path loss whose absolute value is in good agreement with average measured path loss.

Wave Propagation into Buildings

Journal of Applied and Emerging Sciences, 2012

This paper investigates radio wave propagation into buildings illuminated from an out- door base station with an antenna above the rooftop. Field strength measurements are taken in four buildings in urban microcells. Results of our experiments as well as those of several other authors are analyzed and the important factors influencing building penetration loss have been discussed namely angle of incidence, external wall configuration, receiver height and significance of non-line-of-sight surface of the building.