scholarly journals Measurement-Based 5G Millimeter-Wave Propagation Characterization in Vegetated Suburban Macrocell Environments

2020 ◽  
Author(s):  
Peize Zhang ◽  
Bensheng Yang ◽  
Cheng Yi ◽  
Haiming Wang ◽  
Xiaohu You
Keyword(s):  
Millimeter Wave ◽  
Measurement Data ◽  
Path Loss ◽  
Angular Spread ◽  
Line Of Sight ◽  
Small Scale ◽  
Delay Spread ◽  
Shadow Fading ◽  
Loss Prediction ◽  
The Time Domain

An empirically based analysis of propagation characteristics in two vegetated suburban areas with different types and fractions of vegetation cover in 5G millimeter-wave bands is presented. A basic distance-dependent path loss model with a Gaussian random variance for shadow fading is utilized in accordance with the maximum-power directional and omnidirectional measurement data, therein exploiting significant path loss exponents in the presence of vegetation. In comparison with the existing ITU-R and 3GPP models, the effect of dense-leaved trees on path loss prediction is similar to that of buildings, whereas these standard models are inapplicable for sparse obstacle-line-of-sight (OLoS) links. Consequently, an azimuth-angle-based path loss characterization is proposed considering the antenna pattern, beam misalignment, and blockage effects. Moreover, several composite and cluster-level small-scale channel parameters, such as the number of clusters, delay spread, and angular spread, are extracted. Analysis of the first-arrival cluster in the OLoS setting reveals that forward scattering through foliage is still dominant and is expected to produce a larger azimuth angular spread of the arrival and compact multipath components in the time domain compared with line-of-sight and reflected clusters. Measurement results improve existing 3GPP channel models for suburban macrocell scenarios in millimeter-wave bands.

scholarly journals Measurement-Based 5G Millimeter-Wave Propagation Characterization in Vegetated Suburban Macrocell Environments

2020 ◽  
Author(s):  
Peize Zhang ◽  
Bensheng Yang ◽  
Cheng Yi ◽  
Haiming Wang ◽  
Xiaohu You
Keyword(s):  
Millimeter Wave ◽  
Measurement Data ◽  
Path Loss ◽  
Angular Spread ◽  
Line Of Sight ◽  
Small Scale ◽  
Delay Spread ◽  
Shadow Fading ◽  
Loss Prediction ◽  
The Time Domain

An empirically based analysis of propagation characteristics in two vegetated suburban areas with different types and fractions of vegetation cover in 5G millimeter-wave bands is presented. A basic distance-dependent path loss model with a Gaussian random variance for shadow fading is utilized in accordance with the maximum-power directional and omnidirectional measurement data, therein exploiting significant path loss exponents in the presence of vegetation. In comparison with the existing ITU-R and 3GPP models, the effect of dense-leaved trees on path loss prediction is similar to that of buildings, whereas these standard models are inapplicable for sparse obstacle-line-of-sight (OLoS) links. Consequently, an azimuth-angle-based path loss characterization is proposed considering the antenna pattern, beam misalignment, and blockage effects. Moreover, several composite and cluster-level small-scale channel parameters, such as the number of clusters, delay spread, and angular spread, are extracted. Analysis of the first-arrival cluster in the OLoS setting reveals that forward scattering through foliage is still dominant and is expected to produce a larger azimuth angular spread of the arrival and compact multipath components in the time domain compared with line-of-sight and reflected clusters. Measurement results improve existing 3GPP channel models for suburban macrocell scenarios in millimeter-wave bands.

scholarly journals Analysis of Propagation Characteristics for Various Subway Tunnel Scenarios at 28 GHz

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Chengjian Wang ◽  
Wenli Ji ◽  
Guoxin Zheng ◽  
Asad Saleem
Keyword(s):  
Ray Tracing ◽  
Root Mean Square ◽  
Millimeter Wave ◽  
Measurement Data ◽  
Path Loss ◽  
Small Scale ◽  
Delay Spread ◽  
Mean Square ◽  
Propagation Characteristics ◽  
Subway Tunnels

In order to meet the higher data transmission rate requirements of subway communication services, the millimeter wave (mmWave) broadband communication is considered as a potential solution in 5G technology. Based on the channel measurement data in subway tunnels, this paper uses ray-tracing (RT) simulation to predict the propagation characteristics of the 28 GHz millimeter wave frequency band in different tunnel scenarios. A large number of simulations based on ray-tracing software have been carried out for tunnel models with different bending radiuses and different slopes, and we further compared the simulation results with the real time measurement data of various subway tunnels. The large-scale and small-scale propagation characteristics of the channel, such as path loss (PL), root mean square delay spread (RMS-DS), and angle spread (AS), for different tunnel scenarios are analyzed, and it was found that the tunnel with a greater slope causes larger path loss and root mean square delay spread. Furthermore, in the curved tunnel, the angle spread of the azimuth angle is larger than that in a straight tunnel. The proposed results can provide a reference for the design of future 5G communication systems in subway tunnels.

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.

scholarly journals Investigation of Future 5G-IoT Millimeter-Wave Network Performance at 38 GHz for Urban Microcell Outdoor Environment

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 495 ◽  
Author(s):  
Faizan Qamar ◽  
MHD Nour Hindia ◽  
Kaharudin Dimyati ◽  
Kamarul Ariffin Noordin ◽  
Mohammed Bahjat Majed ◽  
...  
Keyword(s):  
Frequency Spectrum ◽  
Millimeter Wave ◽  
Network Performance ◽  
Geographical Area ◽  
Measurement Data ◽  
Path Loss ◽  
Outdoor Environment ◽  
Line Of Sight ◽  
Loss Model ◽  
Path Loss Model

The advent of fifth-generation (5G) systems and their mechanics have introduced an unconventional frequency spectrum of high bandwidth with most falling under the millimeter wave (mmWave) spectrum. The benefit of adopting these bands of the frequency spectrum is two-fold. First, most of these bands appear to be unutilized and they are free, thus suggesting the absence of interference from other technologies. Second, the availability of a larger bandwidth offers higher data rates for all users, as there are higher numbers of users who are connected in a small geographical area, which is also stated as the Internet of Things (IoT). Nevertheless, high-frequency band poses several challenges in terms of coverage area limitations, signal attenuation, path and penetration losses, as well as scattering. Additionally, mmWave signal bands are susceptible to blockage from buildings and other structures, particularly in higher-density urban areas. Identifying the channel performance at a given frequency is indeed necessary to optimize communication efficiency between the transmitter and receiver. Therefore, this paper investigated the potential ability of mmWave path loss models, such as floating intercept (FI) and close-in (CI), based on real measurements gathered from urban microcell outdoor environments at 38 GHz conducted at the Universiti Teknologi Malaysia (UTM), Kuala Lumpur campus. The measurement data were obtained by using a narrow band mmWave channel sounder equipped with a steerable direction horn antenna. It investigated the potential of the network for outdoor scenarios of line-of-sight (LOS) and non-line-of-sight (NLOS) with both schemes of co- (vertical-vertical) and cross (vertical-horizontal) polarization. The parameters were selected to reflect the performance and the variances with other schemes, such as average users cell throughput, throughput of users that are at cell-edges, fairness index, and spectral efficiency. The outcomes were examined for various antenna configurations as well as at different channel bandwidths to prove the enhancement of overall network performance. This work showed that the CI path loss model predicted greater network performance for the LOS condition, and also estimated significant outcomes for the NLOS environment. The outputs proved that the FI path loss model, particularly for V-V antenna polarization, gave system simulation results that were unsuitable for the NLOS scenario.

scholarly journals Vehicle-to-Vehicle Channel Characterization Based on Ray-Tracing for Urban Road Scenarios

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lei Xiong ◽  
Zhiyi Yao ◽  
Haiyang Miao ◽  
Bo Ai
Keyword(s):  
Ray Tracing ◽  
Path Loss ◽  
Angular Spread ◽  
Line Of Sight ◽  
Delay Spread ◽  
Urban Road ◽  
Rms Delay Spread ◽  
Channel Characteristics ◽  
Vehicle To Vehicle ◽  
Simulation Results

In this paper, the vehicle-to-vehicle (V2V) channel characteristics in peak hours at the 5.9 GHz band in two typical urban road scenarios, the urban straight road and the intersection, are investigated. The channel characteristics, such as path loss, root mean square (RMS) delay spread, and angular spread, are derived from the ray-tracing (RT) simulations. Due to the low height of antennas at both the transmitter (Tx) and the receiver (Rx), the line of sight (LOS) between the Tx and the Rx will often be obstructed by other vehicles. Based on the RT simulation results, the shadowing loss is modelled by the multimodal Gaussian distribution, and path loss models in both LOS and non-LOS (NLOS) conditions are obtained. And the RMS delay spread in two scenarios can be modelled by the Weibull distribution. In addition, the deployment of an antenna array is discussed based on the statistics distribution of the angular spread.

scholarly journals Survey of Millimeter-Wave Propagation Measurements and Models in Indoor Environments

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1653
Author(s):  
Ahmed Al-Saman ◽  
Michael Cheffena ◽  
Olakunle Elijah ◽  
Yousef A. Al-Gumaei ◽  
Sharul Kamal Abdul Rahim ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Measurement Techniques ◽  
Path Loss ◽  
Delay Spread ◽  
Indoor Environments ◽  
Future Trends ◽  
Signal Loss ◽  
Indoor Wireless ◽  
The Future ◽  
Future Demands

The millimeter-wave (mmWave) is expected to deliver a huge bandwidth to address the future demands for higher data rate transmissions. However, one of the major challenges in the mmWave band is the increase in signal loss as the operating frequency increases. This has attracted several research interests both from academia and the industry for indoor and outdoor mmWave operations. This paper focuses on the works that have been carried out in the study of the mmWave channel measurement in indoor environments. A survey of the measurement techniques, prominent path loss models, analysis of path loss and delay spread for mmWave in different indoor environments is presented. This covers the mmWave frequencies from 28 GHz to 100 GHz that have been considered in the last two decades. In addition, the possible future trends for the mmWave indoor propagation studies and measurements have been discussed. These include the critical indoor environment, the roles of artificial intelligence, channel characterization for indoor devices, reconfigurable intelligent surfaces, and mmWave for 6G systems. This survey can help engineers and researchers to plan, design, and optimize reliable 5G wireless indoor networks. It will also motivate the researchers and engineering communities towards finding a better outcome in the future trends of the mmWave indoor wireless network for 6G systems and beyond.

The 5-GHz Airport Surface Area Channel—Part I: Measurement and Modeling Results for Large Airports

2008 ◽  
Vol 57 (4) ◽  
pp. 2014-2026 ◽  
Author(s):  
David W. Matolak ◽  
Indranil Sen ◽  
Wenhui Xiong
Keyword(s):  
Path Loss ◽  
Correlation Coefficients ◽  
Line Of Sight ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
Amplitude Data ◽  
Amplitude Correlation ◽  
5 Ghz ◽  
Best Fit ◽  
Probability Density Function Pdf

We describe results from a channel measurement and modeling campaign for the airport surface environment in the 5-GHz band. Using a 50-MHz bandwidth test signal, thousands of power delay profiles (PDPs) were obtained and processed to develop empirical tapped-delay line statistical channel models for large airports. A log-distance path loss model was also developed. The large airport surface channel is classified into three propagation regions, and models are presented for each of the regions for two values of bandwidth. Values of the median root-mean-square (RMS) delay spread range from 500 to 1000 ns for these airports, with the 90 th percentile RMS delay spreads being approximately 1.7 ms. Corresponding correlation bandwidths (i.e., correlation value 1/2) range from approximately 1.5 MHz in non-line-of-sight (NLOS) settings to 17.5 MHz in line-of-sight (LOS) settings. Two types of statistical nonstationarity were also observed: 1) multipath component persistence and 2) propagation region transitions. We provide the multipath component probability of occurrence models and describe Markov chains that are used for modeling both phenomena. Channel tap amplitude statistics are also provided, using the flexible Weibull probability density function (pdf). This pdf was found to best fit fading tap amplitude data, particularly for frequently observed severe fading, which is characterized by fade probabilities that are worse than the commonly used Rayleigh model. Fading parameters equivalent to Nakagami-m-model values ofmnear 0.7 were often observed (withm= 1 being Rayleigh and m < 1 being worse than Rayleigh). We also provide channel tap amplitude correlation coefficients, which typically range from 0.1 to 0.4 but occasionally take values greater than 0.7.

scholarly journals Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Millimeter Wave Bands for 5G Cellular Communications

2018 ◽  
Vol 8 (4) ◽  
pp. 2254 ◽  
Author(s):  
Mohammed B. Majed ◽  
Tharek A. Rahman ◽  
Omar Abdul Aziz
Keyword(s):  
Communication Networks ◽  
Millimeter Wave ◽  
Wide Spectrum ◽  
Path Loss ◽  
Separation Distance ◽  
Propagation Path ◽  
Delay Spread ◽  
Propagation Time ◽  
60 Ghz ◽  
Rms Delay Spread

The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario.

scholarly journals Wideband and Ultrawideband Channel Models in Working Machine Environment

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Attaphongse Taparugssanagorn ◽  
Matti Hämäläinen ◽  
Jari Iinatti
Keyword(s):  
Exponential Decay ◽  
Radio Channel ◽  
Line Of Sight ◽  
Small Scale ◽  
Delay Spread ◽  
Confined Space ◽  
Rms Delay Spread ◽  
Decay Profile ◽  
Cabin Environment ◽  
Uwb Radio

We present statistical models for wideband and ultrawideband (UWB) radio channels in a working machine cabin environment. Based on a set of measurements, it was found that such a small and confined space causes mostly diffuse multipath scattering rather than specular paths. The amplitude of the channel impulse responses in the wideband case is mostly Rayleigh distributed small-scale fading signal, with only a few paths exhibiting Ricean distributions, whereas the ones in the UWB case tend to be log-normally distributed. For the path amplitude, we suggest an exponential decay profile, which has a constant slope in dB scale, with the corresponding parameters for the UWB case. For the wideband case, a twofold exponential decay profile provides excellent fits to the measured data. It was also noted that the root-mean-square (RMS) delay spread is independent of the line-of-sight/obstructed line-of-sight situations of the channel. The multipath components contributing significant energy play a major role in such a small environment if compared to the direct path. In addition, the radio channel gains are attenuated with the presence of a driver inside the cabin.

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