scholarly journals Joint Position and Time Allocation Optimization of UAV-Aided Wireless Powered Relay Communication Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiaofei Di ◽  
Yang Chen
Keyword(s):  
Energy Source ◽  
Time Allocation ◽  
Communication Systems ◽  
Optimal Time ◽  
Wireless Devices ◽  
Optimal Position ◽  
System A ◽  
Relay Communication ◽  
Aerial Vehicle ◽  
The Internet Of Things

The Internet of things (IoT) has emerged as a platform for connecting massive physical devices to collect and analyze data for decision-making. Wireless devices in IoT are usually energy-constrained and thus need to be powered by a stable and reliable energy source in order to maintain a long network lifetime. An unmanned aerial vehicle (UAV) as an energy source is a proper and applicable way to supply energy to wireless devices in IoT, due to its flexibility and potential of providing line-of-sight (LOS) links for wireless air-to-ground channels. In this paper, a UAV-aided wireless powered relay communication system is presented, where a UAV firstly emits energy to a source and a relay, and then, the source and relay cooperatively transmit information to their destination. To explore the performance limit of the system, a problem is formulated by jointly optimizing the position of the UAV and time allocation to maximize the achievable information rate of the system. By deriving the explicit expressions of the optimal position of UAV and optimal time fraction, the nonconvex optimization problem is efficiently solved. Simulation results show that our proposed method significantly outperforms the benchmark methods.

Security in Smart Healthcare System: A Comprehensive Survey

2017 ◽  
Vol 7 (10) ◽  
pp. 39
Author(s):  
P. Jeyadurga ◽  
S. Ebenezer Juliet ◽  
I. Joshua Selwyn ◽  
P. Sivanisha
Keyword(s):  
Secure Communication ◽  
Smart Cities ◽  
Healthcare Systems ◽  
Internet Security ◽  
Security Risk ◽  
System A ◽  
Smart Healthcare ◽  
Comprehensive Survey ◽  
Healthcare Monitoring ◽  
The Internet Of Things

The Internet of things (IoT) is one of the emerging technologies that brought revolution in many application domains such as smart cities, smart retails, healthcare monitoring and so on. As the physical objects are connected via internet, security risk may arise. This paper analyses the existing technologies and protocols that are designed by different authors to ensure the secure communication over internet. It additionally focuses on the advancement in healthcare systems while deploying IoT services.

scholarly journals Data Downlink System in the Vast IOT Node Condition Assisted by UAV, Large Intelligent Surface, and Power and Data Beacon

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5748
Author(s):  
Zhibo Zhang ◽  
Qing Chang ◽  
Na Zhao ◽  
Chen Li ◽  
Tianrun Li
Keyword(s):  
Communication Systems ◽  
Optimization Problems ◽  
Minimum Energy ◽  
Numerical Algorithms ◽  
Flight Trajectory ◽  
Performance Improvements ◽  
Minimum Energy Consumption ◽  
Significant Performance ◽  
Downlink System ◽  
The Internet Of Things

The future development of communication systems will create a great demand for the internet of things (IOT), where the overall control of all IOT nodes will become an important problem. Considering the essential issues of miniaturization and energy conservation, in this study, a new data downlink system is designed in which all IOT nodes harvest energy first and then receive data. To avoid the unsolvable problem of pre-locating all positions of vast IOT nodes, a device called the power and data beacon (PDB) is proposed. This acts as a relay station for energy and data. In addition, we model future scenes in which a communication system is assisted by unmanned aerial vehicles (UAVs), large intelligent surfaces (LISs), and PDBs. In this paper, we propose and solve the problem of determining the optimal flight trajectory to reach the minimum energy consumption or minimum time consumption. Four future feasible scenes are analyzed and then the optimization problems are solved based on numerical algorithms. Simulation results show that there are significant performance improvements in energy/time with the deployment of LISs and reasonable UAV trajectory planning.

VariableZ0antenna technology: a new approach for IoT wireless

2014 ◽  
Vol 7 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Richard A. Formato
Keyword(s):  
Internet Of Things ◽  
Degree Of Freedom ◽  
The Internet ◽  
Simple Design ◽  
Wireless Devices ◽  
Decision Space ◽  
New Approach ◽  
Optimization Methodology ◽  
The Internet Of Things

Variable Z0(VZ0) antenna technology is a new design or optimization methodology applicable to any antenna on any platform designed or optimized with any procedure. It should be particularly useful for wireless devices populating the Internet of Things. VZ0expands the design or decision space by adding another degree of freedom invariably leading to better antennas. A simple design example illustrates its effectiveness.

IoT Recommender System: A Recommender System Based on Sensors from the Internet of Things for Points of Interest

2019 ◽  
pp. 237-250
Author(s):  
Cristian González García ◽  
Daniel Meana-Llorián ◽  
Vicente García Díaz ◽  
Edward Rolando Núñez-Valdez
Keyword(s):  
Internet Of Things ◽  
Recommender System ◽  
The Internet ◽  
System A ◽  
Points Of Interest ◽  
The Internet Of Things

scholarly journals Prediction of Experimental Electromagnetic Coupling to a UAV Model Using Characteristic Mode Analysis

2021 ◽  
Author(s):  
Mohamed Hamdalla ◽  
Benjamin Bissen ◽  
James D. Hunter ◽  
Liu Yuanzhuo ◽  
Victor Khilkevich ◽  
...  
Keyword(s):  
Experimental Measurement ◽  
Experimental Approach ◽  
Electromagnetic Coupling ◽  
Mode Analysis ◽  
Angle Of Incidence ◽  
Characteristic Mode ◽  
System A ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Excitation Conditions

<p>In this work, we study the current coupled to a simplified Unmanned Aerial Vehicle (UAV) model using a dual computational and experimental approach. The surrogate structure reduced the computational burden and facilitated the experimental measurement of the coupled currents. For a practical system, a wide range of simulations and measurements must be performed to analyze the induced current variations with respect to the incident excitation properties such as the frequency, angle of incidence, and polarization. To simplify this analysis, Characteristic Mode Analysis (CMA) was used to compute the eigen-currents of the UAV model and predict where and under which RF excitation conditions, the coupled current is maximized. We verified these predictions using direct experimental measurement of the coupled currents. The presented simulations and measurements show the usefulness of CMA for studying electromagnetic coupling to practical systems. </p>

scholarly journals Prediction of Experimental Electromagnetic Coupling to a UAV Model Using Characteristic Mode Analysis

2021 ◽  
Author(s):  
Mohamed Hamdalla ◽  
Benjamin Bissen ◽  
James D. Hunter ◽  
Liu Yuanzhuo ◽  
Victor Khilkevich ◽  
...  
Keyword(s):  
Experimental Measurement ◽  
Experimental Approach ◽  
Electromagnetic Coupling ◽  
Mode Analysis ◽  
Angle Of Incidence ◽  
Characteristic Mode ◽  
System A ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Excitation Conditions

<p>In this work, we study the current coupled to a simplified Unmanned Aerial Vehicle (UAV) model using a dual computational and experimental approach. The surrogate structure reduced the computational burden and facilitated the experimental measurement of the coupled currents. For a practical system, a wide range of simulations and measurements must be performed to analyze the induced current variations with respect to the incident excitation properties such as the frequency, angle of incidence, and polarization. To simplify this analysis, Characteristic Mode Analysis (CMA) was used to compute the eigen-currents of the UAV model and predict where and under which RF excitation conditions, the coupled current is maximized. We verified these predictions using direct experimental measurement of the coupled currents. The presented simulations and measurements show the usefulness of CMA for studying electromagnetic coupling to practical systems. </p>

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