scholarly journals Statistical Analysis of Radio Propagation Channel in Ruins Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Jiao He ◽  
Er-Ping Li ◽  
Sai-Qiong Zhou ◽  
Kun Liao
Keyword(s):  
Radio Channel ◽  
Channel Modeling ◽  
High Density ◽  
Delay Spread ◽  
Comparison Analysis ◽  
Channel Characteristics ◽  
Channel Parameters ◽  
Good Agreement ◽  
Channel Simulator

The cellphone based localization system for search and rescue in complex high density ruins has attracted a great interest in recent years, where the radio channel characteristics are critical for design and development of such a system. This paper presents a spatial smoothing estimation via rotational invariance technique (SS-ESPRIT) for radio channel characterization of high density ruins. The radio propagations at three typical mobile communication bands (0.9, 1.8, and 2 GHz) are investigated in two different scenarios. Channel parameters, such as arrival time, delays, and complex amplitudes, are statistically analyzed. Furthermore, a channel simulator is built based on these statistics. By comparison analysis of average excess delay and delay spread, the validation results show a good agreement between the measurements and channel modeling results.

scholarly journals Analysis of Non-Stationarity for 5.9 GHz Channel in Multiple Vehicle-to-Vehicle Scenarios

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3626
Author(s):  
Fang Li ◽  
Wei Chen ◽  
Yishui Shui
Keyword(s):  
Transmission Rate ◽  
Radio Channel ◽  
Vertical Direction ◽  
Statistical Characteristics ◽  
Small Scale ◽  
Delay Spread ◽  
Important Indicator ◽  
Power Delay Profile ◽  
Channel Characteristics ◽  
Vehicle To Vehicle

The vehicle-to-vehicle (V2V) radio channel is non-stationary due to the rapid movement of vehicles. However, the stationarity of the V2V channels is an important indicator of the V2V channel characteristics. Therefore, we analyzed the non-stationarity of V2V radio channels using the local region of stationarity (LRS). We selected seven scenarios, including three directions of travel, i.e., in the same, vertical, and opposite directions, and different speeds and environments in a similar driving direction. The power delay profile (PDP) and LRS were estimated from the measured channel impulse responses. The results show that the most important influences on the stationary times are the direction and the speed of the vehicles. The average stationary times for driving in the same direction range from 0.3207 to 1.9419 s, the average stationary times for driving in the vertical direction are 0.0359–0.1348 s, and those for driving in the opposite direction are 0.0041–0.0103 s. These results are meaningful for the analysis of the statistical characteristics of the V2V channel, such as the delay spread and Doppler spread. Small-scale fading based on the stationary times affects the quality of signals transmitted in the V2V channel, including the information transmission rate and the information error code rate.

scholarly journals Measurement and Simulation for Vehicle-to-Infrastructure Communications at 3.5 GHz for 5G

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yi Zeng ◽  
Haofan Yi ◽  
Zijie Xia ◽  
Shaoshi Wang ◽  
Bo Ai ◽  
...  
Keyword(s):  
Intelligent Transportation System ◽  
Path Loss ◽  
Mobile Network ◽  
System Level ◽  
Delay Spread ◽  
Channel Measurements ◽  
Traffic Light ◽  
Channel Characteristics ◽  
Channel Parameters ◽  
Vehicle To Infrastructure

Intelligent Transportation System (ITS) is more and more crucial in the modern transportation field, such as the applications of autonomous vehicles, dynamic traffic light sequences, and automatic road enforcement. As the upcoming fifth-generation mobile network (5G) is entering the deployment phase, the idea of cellular vehicle-to-everything (C-V2X) is proposed. The same 5G networks, coming to mobile phones, will also allow vehicles to communicate wirelessly with each other. Hence, 3.5 GHz, as the main sub-6 GHz band licensed in 5G, is focused in our study. In this paper, a comprehensive study on the channel characteristics for vehicle-to-infrastructure (V2I) link at 3.5 GHz frequency band is conducted through channel measurements and ray-tracing (RT) simulations. Firstly, the channel parameters of the V2I link are characterized based on the measurements, including power delay profile (PDP), path loss, root-mean-square (RMS) delay spread, and coherence bandwidth. Then, the measurement-validated RT simulator is utilized to conduct the simulations in order to supplement other channel parameters, in terms of the Ricean K-factor, angular spreads, the cross-correlations of abovementioned parameters, and the autocorrelation of each parameter itself. This work is aimed at helping the researchers understand the channel characteristics of the V2I link at 3.5 GHz and support the link-level and system level design for future vehicular communications of 5G.

scholarly journals Propagation Measurements at 2.4 GHz Inside a University Building and Estimation of Saleh- Valenzuela Parameters

2007 ◽  
Vol 3 (2) ◽  
pp. 99 ◽  
Author(s):  
Zoran Blažević ◽  
Igor Zanchi ◽  
Ivan Marinović
Keyword(s):  
Indoor Environment ◽  
Spatial Information ◽  
Delay Spread ◽  
Original Form ◽  
Density Functions ◽  
Network Analyzer ◽  
Channel Parameters ◽  
The One ◽  
Propagation Scenario ◽  
Good Agreement

In this paper we analyze measurements conducted in an indoor environment of our university building at a centralfrequency of 2.4 GHz in terms of the Saleh-Valenzuela channel. The channel parameters are extrapolated by processing the power-delay profiles measured by a vector network analyzer. Final adjustments of the parameters are obtained by comparison of simulated and measured delay-spread cumulative density functions, where a quite good agreement between the two is obtained. The predictions of the coherence bandwidth are satisfactory as well. We also considered some extensions to the original form of the model and concluded that the one that would be worthy to apply is the one that, besides temporal, incorporates also spatial information about the channel, whereas other modifications are found to be unnecessary or even unjustified for evaluation of this indoor propagation scenario.

scholarly journals Channel Characteristics of Rail Traffic Tunnel Scenarios Based on Ray-Tracing Simulator

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jinmeng Zhao ◽  
Lei Xiong ◽  
Danping He ◽  
Jiadong Du
Keyword(s):  
Ray Tracing ◽  
Cross Sections ◽  
Radio Channel ◽  
Path Loss ◽  
Vehicle Body ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
Channel Characteristics ◽  
K Factor ◽  
Side Walls

The tunnel scenario is a major rail communication scenario. In this paper, the radio channel characteristics of tunnel scenarios with different carrier frequencies, different distances between the transmitter (Tx) and receiver (Rx), and cross sections are simulated with a ray-tracing tool. Key parameters such as path loss, Rician K-factor, root mean square (RMS) delay spread, and angular spread are studied. According to the results, higher frequencies introduce larger path loss and the presence of the vehicle body increases the path loss by about 35 dB in the scenario; at the same time it will also cause the fluctuation and instability of the path loss. Besides, the influence of reflections from the side walls is significant on radio propagation. The channel experiences more severe fading in a narrow tunnel compared with others.

scholarly journals Directive mmWave radio channel modeling in a ship hull

2021 ◽  
pp. 1-12
Author(s):  
Brecht De Beelde ◽  
Andrés Almarcha Lopéz ◽  
David Plets ◽  
Marwan Yusuf ◽  
Emmeric Tanghe ◽  
...  
Keyword(s):  
Radio Channel ◽  
Path Loss ◽  
Channel Modeling ◽  
Ship Hull ◽  
Line Of Sight ◽  
Delay Spread ◽  
60 Ghz ◽  
Channel Measurements ◽  
Channel Sounder ◽  
Path Distance

Abstract Wireless connectivity has been realized for multiple environments and different frequency bands. However, little research exists about mmWave communication in industrial environments. This paper presents the 60 GHz double-directional radio channel for mmWave communication in a ship hull for Line-of-Sight (LOS) and non-Line-of-Sight (NLOS) conditions. We performed channel measurements using the Terragraph channel sounder at different locations in the ship hull and fitted LOS path loss to a one-slope path loss model. Path loss and root-mean-square delay spread of the LOS path is compared to the reflected path with lowest path loss. NLOS communication via this first-order reflected path is modeled by calculating the path distance and determining the reflection loss. The reflection losses have a considerable contribution to the signal attenuation of the reflected path. The channel models are implemented in an indoor coverage prediction tool, which was extended with a ray launching algorithm and validated by comparison with an analytical electromagnetic solver. The results show that the mmWave radio channel allows high-throughput communication within a ship hull compartment, even when no LOS path between the transmitter and receiver is present.

scholarly journals Radio Propagation Measurements and Cluster-Based Analysis for 5G Millimeter-Wave Cellular Systems in Dense Urban Environments

2020 ◽  
Author(s):  
Peize Zhang ◽  
Bensheng Yang ◽  
Haiming Wang ◽  
Cheng-Xiang Wang ◽  
Xiaohu You
Keyword(s):  
Millimeter Wave ◽  
High Efficiency ◽  
Channel Modeling ◽  
Urban Environments ◽  
Cellular Systems ◽  
Radio Propagation ◽  
Delay Spread ◽  
Multiple Reflections ◽  
Cluster Number ◽  
Channel Characteristics

Empirical channel modeling is necessary for the deployment of the fifth-generation (5G) millimeter-wave (mmWave) cellular system in actual environments. In this paper, cluster-based analyses of mmWave channel characteristics in two typical dense urban environments are performed. First, radio propagation measurement campaigns are conducted at two primary 5G bands of 28 GHz and 39 GHz in a central business district and a dense residential area. The custom-designed channel sounder supports high-efficiency directional scanning sounding, which helps to collect sufficient data for statistical channel modeling. Next, using an improved autoclustering algorithm, multipath clusters and their scattering sources are identified. Mapping results show that multiple reflections from exterior walls and diffraction over building corners or rooftops enhance the coverage for non-line-of-sight (NLoS) links and the influences of these propagation mechanisms are intuitively embodied as changes in the topologies of deployment environments. Finally, an appropriate measure for cluster-level channel characteristics is provided including cluster number, Ricean K-factor, root mean squared (RMS) delay spread, RMS angular spread, and their correlations. Comparisons of these parameters across two mmWave bands are also given. The measurement and modeling results shed light on a fully understanding of mmWave channels in dense urban environments across multiple bands.

scholarly journals Radio Propagation Measurements and Cluster-Based Analysis for 5G Millimeter-Wave Cellular Systems in Dense Urban Environments

2020 ◽  
Author(s):  
Peize Zhang ◽  
Bensheng Yang ◽  
Haiming Wang ◽  
Cheng-Xiang Wang ◽  
Xiaohu You
Keyword(s):  
Millimeter Wave ◽  
High Efficiency ◽  
Channel Modeling ◽  
Urban Environments ◽  
Cellular Systems ◽  
Radio Propagation ◽  
Delay Spread ◽  
Multiple Reflections ◽  
Cluster Number ◽  
Channel Characteristics

Empirical channel modeling is necessary for the deployment of the fifth-generation (5G) millimeter-wave (mmWave) cellular system in actual environments. In this paper, cluster-based analyses of mmWave channel characteristics in two typical dense urban environments are performed. First, radio propagation measurement campaigns are conducted at two primary 5G bands of 28 GHz and 39 GHz in a central business district and a dense residential area. The custom-designed channel sounder supports high-efficiency directional scanning sounding, which helps to collect sufficient data for statistical channel modeling. Next, using an improved autoclustering algorithm, multipath clusters and their scattering sources are identified. Mapping results show that multiple reflections from exterior walls and diffraction over building corners or rooftops enhance the coverage for non-line-of-sight (NLoS) links and the influences of these propagation mechanisms are intuitively embodied as changes in the topologies of deployment environments. Finally, an appropriate measure for cluster-level channel characteristics is provided including cluster number, Ricean K-factor, root mean squared (RMS) delay spread, RMS angular spread, and their correlations. Comparisons of these parameters across two mmWave bands are also given. The measurement and modeling results shed light on a fully understanding of mmWave channels in dense urban environments across multiple bands.

scholarly journals Millisecond lattice gasification for high-density CO2- and O2-sieving nanopores in single-layer graphene

2021 ◽  
Vol 7 (9) ◽  
pp. eabf0116
Author(s):  
Shiqi Huang ◽  
Shaoxian Li ◽  
Luis Francisco Villalobos ◽  
Mostapha Dakhchoune ◽  
Marina Micari ◽  
...  
Keyword(s):  
Single Layer ◽  
High Density ◽  
Single Layer Graphene ◽  
Pore Density ◽  
Vacancy Defects ◽  
Carbon Gasification ◽  
Layer Graphene ◽  
Gas Molecules ◽  
Good Agreement

Etching single-layer graphene to incorporate a high pore density with sub-angstrom precision in molecular differentiation is critical to realize the promising high-flux separation of similar-sized gas molecules, e.g., CO2 from N2. However, rapid etching kinetics needed to achieve the high pore density is challenging to control for such precision. Here, we report a millisecond carbon gasification chemistry incorporating high density (>1012 cm−2) of functional oxygen clusters that then evolve in CO2-sieving vacancy defects under controlled and predictable gasification conditions. A statistical distribution of nanopore lattice isomers is observed, in good agreement with the theoretical solution to the isomer cataloging problem. The gasification technique is scalable, and a centimeter-scale membrane is demonstrated. Last, molecular cutoff could be adjusted by 0.1 Å by in situ expansion of the vacancy defects in an O2 atmosphere. Large CO2 and O2 permeances (>10,000 and 1000 GPU, respectively) are demonstrated accompanying attractive CO2/N2 and O2/N2 selectivities.

scholarly journals Characterization of Tiled Architecture for C-Band 1-Bit Beam-Steering Transmitarray

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1259
Author(s):  
Dmitry Kozlov ◽  
Irina Munina ◽  
Pavel Turalchuk ◽  
Vitalii Kirillov ◽  
Alexey Shitvov ◽  
...  
Keyword(s):  
Communication Systems ◽  
Beam Steering ◽  
Unit Cell ◽  
Electromagnetic Simulations ◽  
Fifth Generation ◽  
Full Wave ◽  
Array Architecture ◽  
Modulation Pattern ◽  
Good Agreement

A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range. A compact circuit model of the tiled unit cell is proposed and characterized with full-wave electromagnetic simulations. Waveguide measurements of a prototype unit cell have been carried out. A design example of a tiled 10 × 10-element 1-bit beam-steering transmitarray is presented and its performance benchmarked against the conventional single-panel, i.e., unibody, counterpart. Prototypes of the tiled and single-panel C-band transmitarrays have been fabricated and tested, demonstrating their close performance, good agreement with simulations and a weak effect of fabrication tolerances. The proposed transmitarray antenna configuration has great potential for fifth-generation (5G) communication systems.

Sign in / Sign up

Export Citation Format

Share Document