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.

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.

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 Statistical Analysis of 5G Channel Propagation using MIMO and Massive MIMO Technologies

2021 ◽  
Vol 11 (4) ◽  
pp. 7417-7423
Author(s):  
Z. A. Shamsan
Keyword(s):  
Antenna Arrays ◽  
Massive Mimo ◽  
Multiple Input Multiple Output ◽  
Small Scale ◽  
Delay Spread ◽  
Band Frequency ◽  
Power Delay Profile ◽  
Mimo Antenna ◽  
Rms Delay Spread ◽  
Path Lengths

Multiple Input Multiple Output (MIMO) and massive MIMO technologies play a significant role in mitigating five generation (5G) channel propagation impairments. These impairments increase as frequency increases, and they become worse at millimeter-waves (mmWaves). They include difficulties of material penetration, Line-of-Sight (LoS) inflexibility, small cell coverage, weather circumstances, etc. This paper simulates the 5G channel at the E-band frequency using the Monte Carlo approach-based NYUSIM tool. The urban microcell (UMi) is the communication environment of this simulation. Both MIMO and massive MIMO use uniformly spaced rectangular antenna arrays (URA). This study investigates the effects of MIMO and massive MIMO on LOS and Non-LOS (NLOS) environments. The simulations considered directional and omnidirectional antennas, the Power Delay Profile (PDP), Root Mean Square (RMS) delay spread, and small-scale PDP for both LOS and NLOS environments. As expected, the wide variety of the results showed that the massive MIMO antenna outperforms the MIMO antenna, especially in terms of the signal power received at the end-user and for longer path lengths.

scholarly journals RMS Delay Spread vs. Coherence Bandwidth from 5G Indoor Radio Channel Measurements at 3.5 GHz Band

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 750 ◽  
Author(s):  
Wout Debaenst ◽  
Arne Feys ◽  
Iñigo Cuiñas ◽  
Manuel García Sánchez ◽  
Jo Verhaevert
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
Radio Channel ◽  
Measurement Data ◽  
Center Frequency ◽  
Fourth Generation ◽  
Delay Spread ◽  
Indoor Environments ◽  
Channel Measurements ◽  
Rms Delay Spread

Our society has become fully submersed in fourth generation (4G) technologies, setting constant connectivity as the norm. Together with self-driving cars, augmented reality, and upcoming technologies, the new generation of Internet of Things (IoT) devices is pushing the development of fifth generation (5G) communication systems. In 5G architecture, increased capacity, improved data rate, and decreased latency are the objectives. In this paper, a measurement campaign is proposed; we focused on studying the propagation properties of microwaves at a center frequency of 3.5 GHz, commonly used in 5G cellular networks. Wideband measurement data were gathered at various indoor environments with different dimensions and characteristics. A ray-tracing analysis showed that the power spectrum is dominated by the line of sight component together with reflections on two sidewalls, indicating the practical applicability of our results. Two wideband parameters, root mean square delay spread and coherence bandwidth, were estimated for the considered scenarios, and we found that they are highly dependent on the physical dimension of the environment rather than on furniture present in the room. The relationship between both parameters was also investigated to provide support to network planners when obtaining the bandwidth from the delay spread, easily computed by a ray-tracing tool.

scholarly journals Vehicular Channel in Urban Environments at 23 GHz for Flexible Access Common Spectrum Application

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Longhe Wang ◽  
Bo Ai ◽  
Jingya Yang ◽  
Hao Qiu ◽  
Wanqiao Wang ◽  
...  
Keyword(s):  
Mobile Networks ◽  
Dynamic Spectrum Access ◽  
Radio Channel ◽  
Path Loss ◽  
Radio Spectrum ◽  
Urban Environments ◽  
Delay Spread ◽  
Access Technology ◽  
Rms Delay Spread ◽  
New Radio

With the development of the vehicular network, new radio technologies have been in the spotlight for maximizing the utilization of the limited radio spectrum resource while accommodating the increasing amount of services and applications in the wireless mobile networks. New spectrum policies based on dynamic spectrum access technology such as flexible access common spectrum (FACS) have been adopted by the Korea Communications Commission (KCC). 23 GHz bands have been allocated to FACS bands by the KCC, which is expected extensively for vehicular communications. The comprehensive knowledge on the radio channel is essential to effectively support the design, simulation, and development of such radio technologies. In this paper, the characteristics of 23 GHz vehicle-to-infrastructure (V2I) channels are simulated and extracted for the urban environment in Seoul. The path loss, shadow factor, Ricean K-factor, root-mean-square (RMS) delay spread, and angular spreads are characterized from the calibrated ray-tracing simulation results, and it can help researchers have a better understanding of the propagation channel for designing vehicular radio technologies and a communication system in a similar environment.

scholarly journals UWB Radio Propagation Measurements in a Desktop Environment

2010 ◽  
Vol 6 (2) ◽  
pp. 74
Author(s):  
Duje Čoko ◽  
Dinko Begušić ◽  
Zoran Blažević
Keyword(s):  
Radio Propagation ◽  
Ultra Wideband ◽  
Delay Spread ◽  
Personal Area Networks ◽  
Network Analyzer ◽  
Wireless Personal Area Networks ◽  
Impulse Responses ◽  
Rms Delay Spread ◽  
Measurement Results ◽  
Uwb Radio

The ultra-wideband wireless personal area networks are expected to be most commonly employed in desktop environments. This paper presents a measurement campaignconducted on a typical office desk. A pair of omnidirectionalUWB antennas and a vector network analyzer were used tomeasure the impulse responses over a frequency rang spanning from 6 GHz to 8.5 GHz, in accordance with the UWB regulations in Europe. The coherence bandwidth and the rms delay spread are calculated from the measurement results. A significant correlation between these wideband parameters is found, but only at higher correlation thresholds.

scholarly journals Channel Measurements and Modeling at 6 GHz in the Tunnel Environments for 5G Wireless Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Shuang-de Li ◽  
Yuan-jian Liu ◽  
Le-ke Lin ◽  
Zhong Sheng ◽  
Xiang-chen Sun ◽  
...  
Keyword(s):  
Path Loss ◽  
Measured Data ◽  
Line Of Sight ◽  
Delay Spread ◽  
Channel Measurements ◽  
Angle Of Arrival ◽  
Rms Delay Spread ◽  
K Factor ◽  
Reference Distance ◽  
Loss Models

Propagation measurements of wireless channels performed in the tunnel environments at 6 GHz are presented in this paper. Propagation characteristics are simulated and analyzed based on the method of shooting and bouncing ray tracing/image (SBR/IM). A good agreement is achieved between the measured results and simulated results, so the correctness of SBR/IM method has been validated. The measured results and simulated results are analyzed in terms of path loss models, received power, root mean square (RMS) delay spread, Ricean K-factor, and angle of arrival (AOA). The omnidirectional path loss models are characterized based on close-in (CI) free-space reference distance model and the alpha-beta-gamma (ABG) model. Path loss exponents (PLEs) are 1.50–1.74 in line-of-sight (LOS) scenarios and 2.18–2.20 in non-line-of-sight (NLOS) scenarios. Results show that CI model with the reference distance of 1 m provides more accuracy and stability in tunnel scenarios. The RMS delay spread values vary between 2.77 ns and 18.76 ns. Specially, the Poisson distribution best fits the measured data of RMS delay spreads for LOS scenarios and the Gaussian distribution best fits the measured data of RMS delay spreads for NLOS scenarios. Moreover, the normal distribution provides good fits to the Ricean K-factor. The analysis of the abovementioned results from channel measurements and simulations may be utilized for the design of wireless communications of future 5G radio systems at 6 GHz.

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.

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