Beyond line-of-sight UAS communication link simulation

2016 ◽  
Author(s):  
Antonio Lamounier Soares Lira da Silva ◽  
Gustavo de Carvalho Bertoli ◽  
Ricardo Pereira Tosta ◽  
Matheus Araujo Ribeiro ◽  
Geraldo Jose Adabo
Keyword(s):  
Line Of Sight ◽  
Communication Link

scholarly journals Analysis of transmission characteristics of non-line-of-sight ultraviolet light under complex channel conditions

2021 ◽  
Vol 336 ◽  
pp. 01012
Author(s):  
Xuan Zheng ◽  
Yanfeng Tang ◽  
Jingyi Du
Keyword(s):  
Ultraviolet Light ◽  
Path Loss ◽  
Mie Scattering ◽  
Spherical Particles ◽  
Dust Particles ◽  
Line Of Sight ◽  
Communication Link ◽  
Communication Quality ◽  
Long Distance ◽  
Non Line Of Sight

Using the multiple scattering model of non-line-of-sight ultraviolet light to simulate and analyze the atmospheric channel characteristics in the complex environment of haze and dust. The Mie scattering theory and T matrix method are used to analyze the path loss of spherical particles and non-spherical particles with particle concentration at different communication distances. The results show that when the communication distance is less than 50 meters, the communication quality under severe haze is the best, and for long-distance communication, the path loss under severe haze increases almost proportionally. In the non-line-of-sight ultraviolet light communication link, the higher the concentration of dust particles, the better the communication quality of the non-line-of-sight ultraviolet light communication transmission. Analysis of the scattering coefficient of spherical particles is significantly greater than that of non-spherical particles.

scholarly journals Strategies for Deploying a Sensor Network to Explore Planetary Lava Tubes

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6203
Author(s):  
Himangshu Kalita ◽  
Jekan Thangavelautham
Keyword(s):  
Low Cost ◽  
Line Of Sight ◽  
Communication Link ◽  
Wireless Power ◽  
Lava Tube ◽  
Long Distance ◽  
Lava Tubes ◽  
Distance Communication ◽  
High Resolution Images ◽  
Exploration Mission

Recently discovered pits on the surface of the Moon and Mars are theorized to be remnants of lava tubes, and their interior may be in pristine condition. Current landers and rovers are unable to access these areas of high interest. However, multiple small, low-cost robots that can utilize unconventional mobility through ballistic hopping can work as a team to explore these environments. In this work, we propose strategies for exploring these newly discovered Lunar and Martian pits with the help of a mother-daughter architecture for exploration. In this architecture, a highly capable rover or lander would tactically deploy several spherical robots (SphereX) that would hop into the rugged pit environments without risking the rover or lander. The SphereX robots would operate autonomously and perform science tasks, such as getting inside the pit entrance, obtaining high-resolution images, and generating 3D maps of the environment. The SphereX robot utilizes the rover or lander’s resources, including the power to recharge and a long-distance communication link to Earth. Multiple SphereX robots would be placed along the theorized caves/lava tube to maintain a direct line-of-sight connection link from the rover/lander to the team of robots inside. This direct line-of-sight connection link can be used for multi-hop communication and wireless power transfer to sustain the exploration mission for longer durations and even lay a foundation for future high-risk missions.

Design and development of a high throughput airborne line-of-sight communication link

2015 ◽  
Vol 132 (6) ◽  
pp. 282-288
Author(s):  
Harald Schlemmer ◽  
Eral Türkyilmaz ◽  
Michael Schmidt ◽  
Johannes Ebert ◽  
Heinz Mayer
Keyword(s):  
High Throughput ◽  
Line Of Sight ◽  
Communication Link ◽  
Design And Development

scholarly journals Investigation of vehicle to vehicle communication system using visible light technology

2021 ◽  
Author(s):  
Hasan Farahneh
Keyword(s):  
Visible Light ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Transportation Systems ◽  
Supervised Machine Learning ◽  
Closed Form Expression ◽  
Line Of Sight ◽  
Attractive Alternative ◽  
Communication Link ◽  
Vehicle To Vehicle

Visible Light Communication (VLC) has emerged as an attractive alternative to radio frequency (RF) communication, due to cost-effectiveness and being license free. It has also proved its applicability in automotive applications, as an alternative and/or a complement to the traditional RF-based communications. We investigate the suitability of VLC in Intelligent Transportation Systems (ITS) and discuss its advantages in terms of safety enhancement and improved efficiency of the ITS. In this thesis, a VLC-based Vehicle-to-Vehicle (V2V) system in practical environments, considering both Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) paths are presented. The thesis investigates robust communication between a Light Emitting Diodes (LEDs) based VLC emitter and Photodiodes (PDs) based VLC receiver. For consideration of a V2V communication system, we consider transmitter on vehicle headlights and receivers on taillight making 2 _ 2 Multiple-Input-Multiple-Output (MIMO) communication link. A closed-form expression of the Channel Impulse Response (CIR) is derived and the effect of various channel parameters is analyzed. Optical-Orthogonal Frequency Division Multiplexing (O-OFDM) with adaptive modulation schemes is proposed for system improvement. Its performance is evaluated in terms of Inter Symbol Interference (ISI) mitigation, and data rate improvement. Moreover, the effect of sunlight on the V2V-VLC Two denoising schemes are proposed and evaluated as a solution to combat the effect of the solar irradiance on the VLC signal. Firstly, we use a differential receiver for denoising purposes followed by k-Nearest Neighbour (kNN) based adaptive _ltering algorithm, which is a supervised Machine Learning (MLE) technique. The shadowing effect is also studied. Moreover, an application of VLC in Foglet based ITS is described. The simulation validation of the VLC-based V2V system is performed under various environmental conditions and scenarios. Obtained results emphasize the suitability of VLC technology for automobile applications,.

scholarly journals EMR: A new metric to assess the resilience of directional mmWave channels to blockages

2021 ◽  
Vol 2 (2) ◽  
pp. 47-60
Author(s):  
Fatih Erden ◽  
Ozgur Ozdemir ◽  
Ismail Guvenc ◽  
David W. Matolak
Keyword(s):  
Communication Systems ◽  
Communication Channel ◽  
Path Loss ◽  
Spatial Diversity ◽  
Line Of Sight ◽  
Communication Link ◽  
Weighted Sum ◽  
Channel Measurements ◽  
Angular Domain ◽  
Cosine Distance

Millimeter-wave (mmWave) communication systems require narrow beams to compensate for high path loss and to increase the communication range. If an obstacle blocks the dominant communication direction, alternative paths (directions) should be quickly identified to maintain reliable connectivity. In this paper, we introduce a new metric to quantify the Effective Multipath Richness (EMR) of a directional communication channel in the angular domain. In particular, the proposed metric takes into account the strength and spatial diversity of the resolved Multipath Components (MPCs), while also considering the beamwidth of the communication link and the blockage characteristics. The metric is defined as a weighted sum of the number of distinct MPC clusters in the angular domain, where the clustering of the MPCs is performed based on the cosine-distance between the dominant MPCs. For a given transmitter (TX) and receiver (RX) pair, the EMR is a single scalar value that characterizes the robustness of the communication link against blockages, as it captures the number of unique communication directions that can be utilized. It is also possible to characterize the blockage robustness for the whole environment by evaluating the spatial distribution of the EMR metric considering various different TX/RX locations. Using our proposed metric, one can assess the scattering richness of different environments to achieve a particular service quality. We evaluate the proposed metric using our 28 GHz channel measurements in a library environment for Line-of-Sight (LOS) and NLOS scenarios, and compare it with some other commonly used propagation metrics. We argue that EMR is especially informative at higher frequencies, e.g., mmWave and terahertz (THz), where the propagation attenuation is high, and directional Non-Light-of-Sight (NLOS) communication is critical for the success of the network.

scholarly journals Investigation of vehicle to vehicle communication system using visible light technology

2021 ◽  
Author(s):  
Hasan Farahneh
Keyword(s):  
Visible Light ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Transportation Systems ◽  
Supervised Machine Learning ◽  
Closed Form Expression ◽  
Line Of Sight ◽  
Attractive Alternative ◽  
Communication Link ◽  
Vehicle To Vehicle

Visible Light Communication (VLC) has emerged as an attractive alternative to radio frequency (RF) communication, due to cost-effectiveness and being license free. It has also proved its applicability in automotive applications, as an alternative and/or a complement to the traditional RF-based communications. We investigate the suitability of VLC in Intelligent Transportation Systems (ITS) and discuss its advantages in terms of safety enhancement and improved efficiency of the ITS. In this thesis, a VLC-based Vehicle-to-Vehicle (V2V) system in practical environments, considering both Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) paths are presented. The thesis investigates robust communication between a Light Emitting Diodes (LEDs) based VLC emitter and Photodiodes (PDs) based VLC receiver. For consideration of a V2V communication system, we consider transmitter on vehicle headlights and receivers on taillight making 2 _ 2 Multiple-Input-Multiple-Output (MIMO) communication link. A closed-form expression of the Channel Impulse Response (CIR) is derived and the effect of various channel parameters is analyzed. Optical-Orthogonal Frequency Division Multiplexing (O-OFDM) with adaptive modulation schemes is proposed for system improvement. Its performance is evaluated in terms of Inter Symbol Interference (ISI) mitigation, and data rate improvement. Moreover, the effect of sunlight on the V2V-VLC Two denoising schemes are proposed and evaluated as a solution to combat the effect of the solar irradiance on the VLC signal. Firstly, we use a differential receiver for denoising purposes followed by k-Nearest Neighbour (kNN) based adaptive _ltering algorithm, which is a supervised Machine Learning (MLE) technique. The shadowing effect is also studied. Moreover, an application of VLC in Foglet based ITS is described. The simulation validation of the VLC-based V2V system is performed under various environmental conditions and scenarios. Obtained results emphasize the suitability of VLC technology for automobile applications,.

Test and Measurement on a 60 GHz Line of Sight (LOS) Communication Link

2003 ◽  
Vol 20 (5) ◽  
pp. 425-431
Author(s):  
R Bera ◽  
Sanjib Sil ◽  
H Sarkar ◽  
J Bera
Keyword(s):  
Line Of Sight ◽  
Communication Link ◽  
60 Ghz
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