scholarly journals Measurements of Building Transmission Loss and Delay Spread at 2.5 GHz

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
L. H. Gonsioroski ◽  
L. da Silva Mello
Keyword(s):  
Transmission Loss ◽  
Signal Transmission ◽  
Delay Spread ◽  
Dispersion Parameters ◽  
Rms Delay Spread ◽  
Urban Buildings ◽  
Time Dispersion ◽  
The Mean ◽  
Mean Excess Delay

This paper presents the results of measurements of signal transmission loss at 2.5 GHz through 10 urban buildings. This allows the characterization of different types of buildings by effective attenuation constants and consideration of the contribution of the transmitted signal in microcell coverage predictions. Power delay profiles (PDPs) of the received signal were also measured and used to determine the time dispersion parameters of the channel, including the mean excess delay and the rms delay spread.

UWB CHANNEL CHARACTERIZATION IN 28 GHZ MILLIMETER WAVEBAND FOR 5G CELLULAR NETWORKS

2016 ◽  
Vol 78 (6-11) ◽  
Author(s):  
Ahmed M. Al-Samman ◽  
Tharek A. Rahman ◽  
Razali Ngah
Keyword(s):  
Cellular Networks ◽  
Cumulative Distribution ◽  
Delay Spread ◽  
Wave Band ◽  
Dispersion Parameters ◽  
Rms Delay Spread ◽  
High Data ◽  
Large Bandwidth ◽  
The Future ◽  
Wideband Channel

The demands of high data rate transmission for future wireless communication technologies are increasing rapidly. The current bands for cellular network will not be able to satisfy these requirements. The millimeter wave (mm-wave) bands are the candidate bands for the future cellular networks. The 28 GHz band is the strongest candidate for 5G cellular networks. The large bandwidth at this band is one of the main parameters that make the mm-wave bands promising candidate for the future cellular networks. To know the wideband channel behavior in mm-wave bands, the wideband channel characterizations are required. In this paper, the 3D WINNER model is used to model the wideband channel at 28 GHz band. Based on this model, the time dispersion parameters at 28 GHz mm-wave band are investigated. The root mean square delay spread and the mean excess delay are the main parameters that can be used to characterize the wideband channel. Morever, the cumulative distribution function (CDF) is used to model the RMS delay spreads. The results show that the RMS delay spread varies between 4.1 ns and 443.7 ns.

scholarly journals Wideband Channel Characterization for 6G Networks in Industrial Environments

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2015
Author(s):  
Ahmed Al-Saman ◽  
Marshed Mohamed ◽  
Michael Cheffena ◽  
Arild Moldsvor
Keyword(s):  
Radio Channel ◽  
Path Loss ◽  
Data Rate ◽  
Delay Spread ◽  
Channel Measurements ◽  
Data Traffic ◽  
Dispersion Parameters ◽  
Time Dispersion ◽  
K Factor ◽  
Industrial Environments

Wireless data traffic has increased significantly due to the rapid growth of smart terminals and evolving real-time technologies. With the dramatic growth of data traffic, the existing cellular networks including Fifth-Generation (5G) networks cannot fully meet the increasingly rising data rate requirements. The Sixth-Generation (6G) mobile network is expected to achieve the high data rate requirements of new transmission technologies and spectrum. This paper presents the radio channel measurements to study the channel characteristics of 6G networks in the 107–109 GHz band in three different industrial environments. The path loss, K-factor, and time dispersion parameters are investigated. Two popular path loss models for indoor environments, the close-in free space reference distance (CI) and floating intercept (FI), are used to examine the path loss. The mean excess delay (MED) and root mean squared delay spread (RMSDS) are used to investigate the time dispersion of the channel. The path loss results show that the CI and FI models fit the measured data well in all industrial settings with a path loss exponent (PLE) of 1.6–2. The results of the K-factor show that the high value in industrial environments at the sub-6 GHz band still holds well in our measured environments at a high frequency band above 100 GHz. For the time dispersion parameters, it is found that most of the received signal energy falls in the early delay bins. This work represents a first step to establish the feasibility of using 6G networks operating above 100 GHz for industrial applications.

scholarly journals Large-Scale Fading and Time Dispersion Parameters of UWB Channel in Underground Mines

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Abdellah Chehri ◽  
Paul Fortier ◽  
Pierre Martin Tardif
Keyword(s):  
Mobile Communications ◽  
Path Loss ◽  
Worker Safety ◽  
Ultra Wideband ◽  
Underground Mines ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
5 Ghz ◽  
Mean Excess Delay ◽  
Uwb Channel

RF channel measurements in underground mines have important applications in the field of mobile communications for improving operational efficiency and worker safety. This paper presents an experimental study of the ultra wideband (UWB) radio channel, based on extensive sounding campaigns covering the underground mine environment. Measurements were carried out in the frequency band of 2–5 GHz. Various communication links were considered including both line-of-sight (LOS) and non-LOS (NLOS) scenarios. In this paper, we are interested in more details of the variations of the RMS delay spread and mean excess delay with Tx/Rx separation, and the variation of RMS with mean excess. The distance dependency of path loss and shadowing fading statistics is also investigated. To give an idea about the behaviour of UWB channel in underground mines, a comparison of our approach with other published works is given including path loss exponent, shadow fading variance, mean excess delay, and RMS delay spread.

scholarly journals Contribution to the Channel Path Loss and Time-Dispersion Characterization in an Office Environment at 26 GHz

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1261 ◽  
Author(s):  
Lorenzo Rubio ◽  
Rafael P. Torres ◽  
Vicent M. Rodrigo Peñarrocha ◽  
Jesús R. Pérez ◽  
Herman Fernández ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Path Loss ◽  
Delay Spread ◽  
Propagation Channel ◽  
Office Environment ◽  
Rms Delay Spread ◽  
Minimum Mean Squared Error ◽  
Time Dispersion ◽  
Reference Distance ◽  
Office Environments

In this paper, path loss and time-dispersion results of the propagation channel in a typical office environment are reported. The results were derived from a channel measurement campaign carried out at 26 GHz in line-of-sight (LOS) and obstructed-LOS (OLOS) conditions. The parameters of both the floating-intercept (FI) and close-in (CI) free space reference distance path loss models were derived using the minimum-mean-squared-error (MMSE). The time-dispersion characteristics of the propagation channel were analyzed through the root-mean-squared (rms) delay-spread and the coherence bandwidth. The results reported here provide better knowledge of the propagation channel features and can be also used to design and evaluate the performance of the next fifth-generation (5G) networks in indoor office environments at the potential 26 GHz frequency band.

scholarly journals Millimeter Wave Propagation Measurements and Characteristics for 5G System

2020 ◽  
Vol 10 (1) ◽  
pp. 335 ◽  
Author(s):  
Ahmed M. Al-Samman ◽  
Marwan Hadri Azmi ◽  
Y. A. Al-Gumaei ◽  
Tawfik Al-Hadhrami ◽  
Tharek Abd. Rahman ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Measurement Data ◽  
Path Loss ◽  
Ultra Wideband ◽  
Line Of Sight ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
5G Systems ◽  
Mean Excess Delay ◽  
Wideband Channel

In future 5G systems, the millimeter wave (mmWave) band will be used to support a large capacity for current mobile broadband. Therefore, the radio access technology (RAT) should be made available for 5G devices to help in distinct situations, for example device-to-device communications (D2D) and multi-hops. This paper presents ultra-wideband channel measurements for millimeter wave bands at 19, 28, and 38 GHz. We used an ultra-wideband channel sounder (1 GHz bandwidth) in an indoor to outdoor (I2O) environment for non-line-of-sight (NLOS) scenarios. In an NLOS environment, there is no direct path (line of sight), and all of the contributed paths are received from different physical objects by refection propagation phenomena. Hence, in this work, a directional horn antenna (high gain) was used at the transmitter, while an omnidirectional antenna was used at the receiver to collect the radio signals from all directions. The path loss and temporal dispersion were examined based on the acquired measurement data—the 5G propagation characteristics. Two different path loss models were used, namely close-in (CI) free space reference distance and alpha-beta-gamma (ABG) models. The time dispersion parameters were provided based on a mean excess delay, a root mean square (RMS) delay spread, and a maximum excess delay. The path loss exponent for this NLOS specific environment was found to be low for all of the proposed frequencies, and the RMS delay spread values were less than 30 ns for all of the measured frequencies, and the average RMS delay spread values were 19.2, 19.3, and 20.3 ns for 19, 28, and 38 GHz frequencies, respectively. Moreover, the mean excess delay values were found also at 26.1, 25.8, and 27.3 ns for 19, 28, and 38 GHz frequencies, respectively. The propagation signal through the NLOS channel at 19, 28, and 38 GHz was strong with a low delay; it is concluded that these bands are reliable for 5G systems in short-range applications.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

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