scholarly journals Low Altitude UAV Air-to-Ground Channel Measurement and Modeling in Semiurban Environments

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhihong Qiu ◽  
Xi Chu ◽  
Cesar Calvo-Ramirez ◽  
César Briso ◽  
Xuefeng Yin
Keyword(s):  
Communication Systems ◽  
Factor Model ◽  
Path Loss ◽  
Propagation Channel ◽  
Channel Changes ◽  
Channel Characteristics ◽  
Air Space ◽  
Multiple Measurements ◽  
Low Altitude ◽  
Different Altitudes

Small- and medium-sized unmanned aerial vehicles (UAVs) can fly for a short distance (<2 km) from a control station in a nonsegregated air space (altitudes < 100 m). It is of great interest to model the propagation channel under such condition, where there is an important influence from the environment. This paper presents multiple measurements carried out in low altitudes with a medium-sized UAV flying over a semiurban environment. Path loss exponent is given based on the measurements done at different altitudes and a height-dependent Rician K factor model is proposed. The results clearly reveal the existence of two propagation zones with very distinct channel characteristics. The breakpoint indicates the height where the condition of the channel changes rapidly. At low altitudes, the obstacles generate a large amount of multipath and the propagation is greatly affected, while at higher altitudes the influence mitigates. Our results are useful for the modeling of low altitude air-to-ground (AG) propagation channels and the performance analysis of UAV-enabling AG communication systems, such as the channel capacity and the throughput.

scholarly journals A Review of Wireless and PLC Propagation Channel Characteristics for Smart Grid Environments

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Sabih Güzelgöz ◽  
Hüseyin Arslan ◽  
Arif Islam ◽  
Alexander Domijan
Keyword(s):  
Smart Grid ◽  
Communication Systems ◽  
Low Voltage ◽  
Path Loss ◽  
Electric Power System ◽  
Channel Characteristics ◽  
Noise Characteristics ◽  
Grid Environments ◽  
Communication Needs ◽  
Smart Grid Communication

Wireless, power line communication (PLC), fiber optic, Ethernet, and so forth are among the communication technologies on which smart grid communication infrastructure is envisioned to be built. Among these, wireless and PLC-based solutions are attractive considering the cost of initial deployment. Wireless communication deployment in smart grid covers a variety of environments such as indoor, outdoor, and electric-power-system facilities. Similar diversity is expected in PLC deployment as well covering low voltage (LV), medium voltage (MV), and high voltage (HV) segments of the grid. In spite of being attractive, wireless and PLC channels are very harsh posing great challenges to performance of communication systems. In proposing solutions to smart grid communication needs, two approaches are likely to be followed. One is based on the use of existing wireless and PLC technologies with some modifications, and the other relies upon developing novel communication protocols particularly addressing the smart grid needs. Both of these approaches require an in-depth knowledge of communication channel characteristics. The aim of this study is to reveal the wireless and PLC channel characteristics of smart grid environments in terms of several parameters such as path loss and attenuation, time dispersion, time selectivity, amplitude statistics, and noise characteristics.

Measurement-Based Propagation Channel Characteristics for Millimeter-Wave 5G Giga Communication Systems

ETRI Journal ◽  
2016 ◽  
Vol 38 (6) ◽  
pp. 1031-1041 ◽  
Author(s):  
Juyul Lee ◽  
Jinyi Liang ◽  
Myung-Don Kim ◽  
Jae-Joon Park ◽  
Bonghyuk Park ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Communication Systems ◽  
Propagation Channel ◽  
Channel Characteristics

scholarly journals Experimental UWB Propagation Channel Path Loss and Time-Dispersion Characterization in a Laboratory Environment

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lorenzo Rubio ◽  
Juan Reig ◽  
Herman Fernández ◽  
Vicent M. Rodrigo-Peñarrocha
Keyword(s):  
Communication Systems ◽  
Path Loss ◽  
Propagation Channel ◽  
Dispersion Parameters ◽  
Laboratory Environment ◽  
High Data ◽  
Time Dispersion ◽  
Data Rates ◽  
Successful Design ◽  
Uwb Channel

The knowledge of the propagation channel properties is an important issue for a successful design of ultrawideband (UWB) communication systems enabling high data rates in short-range applications. From an indoor measurement campaign carried out in a typical laboratory environment, this paper analyzes the path loss and time-dispersion properties of the UWB channel. Values of the path loss exponent are derived for the direct path and for a Rake receiver structure, examining the maximum multipath diversity gain when anallRake (ARake) receiver is used. Also, the relationship between time-dispersion parameters and path loss is investigated. The UWB channel transfer function (CTF) was measured in the frequency domain over a channel bandwidth of 7.5 GHz in accordance with the UWB frequency range (3.1–10.6 GHz).

scholarly journals Spatial characterization of propagation channels for terahertz band

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Bilal Aghoutane ◽  
Mohammed El Ghzaoui ◽  
Hanan El Faylali
Keyword(s):  
Communication Systems ◽  
Indoor Environment ◽  
Channel Model ◽  
Path Loss ◽  
Propagation Loss ◽  
Terahertz Band ◽  
Indoor Scenarios ◽  
Transmission Windows ◽  
Sv Channel

AbstractThe aim of this work consists in characterizing the Terahertz (THz) propagation channel in an indoor environment, in order to propose a channel model for THz bands. We first described a propagation loss model by taking into account the attenuation of the channel as a function of distance and frequency. The impulse response of the channel is then described by a set of rays, characterized by their amplitude, their delay and their phase. Apart from the frequency selective nature, path loss in THz band is also an others issue associated with THz communication systems. This work based on the conventional Saleh-Valenzuela (SV) model which is intended for indoor scenarios. In this paper, we have introduced random variables as Line of sight (LOS) component, and then merging it with the SV channel model to adopt it to the THz context. From simulation, we noted an important effect when the distance between the transmitter and the receiver change. This effect produces variations in frequency loss. The simulations carried out from this model show that to enhance the performance of THz system it is recommended to transmit information over transmission windows instead over the whole band.

scholarly journals Propagation Channel Measurements in the mm- and Sub-mm Wave Range for Different Indoor Communication Scenarios

2021 ◽  
Vol 42 (4) ◽  
pp. 357-370
Author(s):  
M. A. Salhi ◽  
T. Kleine-Ostmann ◽  
T. Schrader
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Wireless Communication Systems ◽  
Electromagnetic Spectrum ◽  
Channel Measurements ◽  
Frequency Range ◽  
Propagation Channel ◽  
Data Rates ◽  
Indoor Wireless ◽  
Wave Range

AbstractIncreasing data rates in wireless communications are accompanied with the need for new unoccupied and unregulated bandwidth in the electromagnetic spectrum. Higher carrier frequencies in the lower THz frequency range might offer the solution for future indoor wireless communication systems with data rates of 100 Gbit/s and beyond that cannot be located elsewhere. In this review, we discuss propagation channel measurements in an extremely broad frequency range from 50 to 325 GHz in selected indoor communication scenarios including kiosk downloading, office room communication, living rooms, and typical industrial environments.

scholarly journals Broadband Wireless Channel in Composite High-Speed Railway Scenario: Measurements, Simulation, and Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianwen Ding ◽  
Lei Zhang ◽  
Jingya Yang ◽  
Bin Sun ◽  
Jiying Huang
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
High Speed ◽  
Channel Model ◽  
High Reliability ◽  
Rapid Development ◽  
Path Loss ◽  
Wireless Channel ◽  
Delay Spread ◽  
High Speed Railway

The rapid development of high-speed railway (HSR) and train-ground communications with high reliability, safety, and capacity promotes the evolution of railway dedicated mobile communication systems from Global System for Mobile Communications-Railway (GSM-R) to Long Term Evolution-Railway (LTE-R). The main challenges for LTE-R network planning are the rapidly time-varying channel and high mobility, because HSR lines consist of a variety of complex terrains, especially the composite scenarios where tunnels, cuttings, and viaducts are connected together within a short distance. Existing researches mainly focus on the path loss and delay spread for the individual HSR scenarios. In this paper, the broadband measurements are performed using a channel sounder at 950 MHz and 2150 MHz in a typical HSR composite scenario. Based on the measurements, the pivotal characteristics are analyzed for path loss exponent, power delay profile, and tap delay line model. Then, the deterministic channel model in which the 3D ray-tracing algorithm is applied in the composite scenario is presented and validated by the measurement data. Based on the ray-tracing simulations, statistical analysis of channel characteristics in delay and Doppler domain is carried out for the HSR composite scenario. The research results can be useful for radio interface design and optimization of LTE-R system.

scholarly journals ANALISIS PROPAGASI PADA KAWASAN KAMPUS UNIVERSITAS NUSA CENDANA PENFUI KUPANG

2019 ◽  
pp. 7-16
Author(s):  
Leonardo F. Lay ◽  
Kalvein Rantelobo ◽  
Beby H. A. Manafe
Keyword(s):  
Communication Systems ◽  
Cost Model ◽  
Path Loss ◽  
Secondary Data ◽  
Propagation Model ◽  
Primary Data ◽  
Acceptance Test ◽  
Test Drive ◽  
Dry Land ◽  
The University

In a telecommunications system, a radio propagation model is needed to do a design, construction, and development of mobile communication systems. Propagation models commonly used are the Okumura-Hatta model and the COST model 231. These models are used to determine an accurate propagation model in a particular area. This study aims to obtain a propagation model on the environmental conditions of dry-land such as the University of Nusa Cendana areas by using Okumura-Hata path loss modeling and COST-231. In this study, the acceptance test drive was carried out at frequencies of 900 Mhz, 1800 Mhz and 1900 MHz using the G-NetTrack application on Telkomsel BTS in the University of Nusa Cendana area with Latitude coordinates -10.156738 and Longitude 123.668422 as well as observing frequencies using Spectrum Analyzer to be used as primary data. The next step is to calculate the received power data as secondary data using the Okumura-Hata path loss calculation and COST-231. Based on primary and secondary data an analysis of which propagation model matches the measurements in the field is carried out. From the propagation analysis, it can be concluded that the propagation model that suits the conditions on the campus area is the Okumura-Hatta model.

scholarly journals A Probabilistic Target Search Algorithm Based on Hierarchical Collaboration for Improving Rapidity of Drones

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2535 ◽  
Author(s):  
Il-Kyu Ha ◽  
You-Ze Cho
Keyword(s):  
High Altitude ◽  
Target Detection ◽  
Information Transfer ◽  
Search Algorithm ◽  
Search Time ◽  
Previous Method ◽  
Target Search ◽  
Low Altitude ◽  
Military Facilities ◽  
Different Altitudes

Finding a target quickly is one of the most important tasks in drone operations. In particular, rapid target detection is a critical issue for tasks such as finding rescue victims during the golden period, environmental monitoring, locating military facilities, and monitoring natural disasters. Therefore, in this study, an improved hierarchical probabilistic target search algorithm based on the collaboration of drones at different altitudes is proposed. This is a method for reducing the search time and search distance by improving the information transfer methods between high-altitude and low-altitude drones. Specifically, to improve the speed of target detection, a high-altitude drone first performs a search of a wide area. Then, when the probability of existence of the target is higher than a certain threshold, the search information is transmitted to a low-altitude drone which then performs a more detailed search in the identified area. This method takes full advantage of fast searching capabilities at high altitudes. In other words, it reduces the total time and travel distance required for searching by quickly searching a wide search area. Several drone collaboration scenarios that can be performed by two drones at different altitudes are described and compared to the proposed algorithm. Through simulations, the performances of the proposed algorithm and the cooperation scenarios are analyzed. It is demonstrated that methods utilizing hierarchical searches with drones are comparatively excellent and that the proposed algorithm is approximately 13% more effective than a previous method and much better compared to other scenarios.

scholarly journals Characterization of Path Loss and Large-Scale Fading for Rapid Intervention Team Communication in Underground Parking Garages

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2431 ◽  
Author(s):  
Seppe Van Brandt ◽  
Robbe Van Thielen ◽  
Jo Verhaevert ◽  
Tanja Van Hecke ◽  
Hendrik Rogier
Keyword(s):  
Large Scale ◽  
Path Loss ◽  
Wireless Channel ◽  
Building Structure ◽  
Propagation Channel ◽  
Parking Garage ◽  
High Penetration ◽  
Parking Garages ◽  
Intervention Team

This paper reports the characterization of the 2.45-GHz-ISM-band radio wave propagation channel. Specifically, measurements were performed in an underground parking garage, with the aim of optimizing breadcrumb systems for a Rapid Intervention Team application. The effects of the high penetration loss and large reflections by the concrete reinforced building structure on the path loss and the large-scale fading were studied. Based on the analysis of the wireless channel, critical points for reliable communication between members of a Rapid Intervention Team were identified. In particular, attention was paid to dealing with large, spatially confined signal losses due to shadowing, the anticipation of corner losses and the ability of the system to operate on multiple floors.

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