scholarly journals Joint UAV channel modeling and power control for 5G IoT networks

Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jatuporn Supramongkonset ◽  
Sarun Duangsuwan ◽  
Myo Myint Maw ◽  
Sathaporn Promwong

The purpose of this work was to investigate the air-to-air channel model (A2A-CM) for unmanned aerial vehicle- (UAV-) enabled wireless communications. Specifically, a low-altitude small UAV needs to characterize the propagation mechanisms from ground reflection. In this paper, the empirical path loss channel characterizations of A2A ground reflection CM based on different scenarios were presented by comparing the wireless communication modules for UAVs. Two types of wireless communication modules both WiFi 2.4 GHz and LoRa 868 MHz frequency were deployed to study the path loss channel characterization between Tx-UAV and Rx-UAV. To investigate the path loss, three types of experimental channel models, such as CM1 grass floor, CM2 soil floor, and CM3 rubber floor, were considered under the ground reflection condition. The analytical A2A Two-Ray (A2AT-R) model and the modified Log-Distance model were simulated to compare the correlation with the measurement data. The measurement results in the CM3 rubber floor scenario showed the impact from the ground reflection at 1 m to 3 m Rx-UAV altitudes both 2.4 GHz and 868 MHz which was converged to the A2AT-R model and related to the modified Log-Distance model above 3 m. It clear that there is no ground reflection effect from the CM1 grass floor and CM2 soil floor. This work showed that the analytical A2AT-R model and the modified Log-Distance model can deploy to model the path loss of A2A-CM by using WiFi and LoRa wireless modules.


2019 ◽  
Vol 9 (3) ◽  
pp. 443 ◽  
Author(s):  
Arafat Habib ◽  
Sangman Moh

Over the past few years, the modeling of wireless channels for radio wave propagation over the sea surface has drawn the attention of many researchers. Channel models are designed and implemented for different frequencies and communication scenarios. There are models that emphasize the influence of the height of the evaporation duct in the marine environment, as well as models that deal with different frequencies (2.5, 5, and 10 GHz, etc.) or the impact of various parameters, such as antenna height. Despite the increasing literature on channel modeling for the over-the-sea marine environment, there is no comprehensive study that focuses on key concepts that need to be considered when developing a new channel model, characteristics of channel models, and comparative analysis of existing works along with their possible improvements and future applications. In this paper, channel models are discussed in relation to their operational principles and key features, and they are compared with each other in terms of major characteristics and pros and cons. Some important insights on the design and implementation of a channel model, possible applications and improvements, and challenging issues and research directions are also discussed. The main goal of this paper is to present a comparative study of over-the-sea channel models for radio wave propagation, so that it can help engineers and researchers in this field to choose or design the appropriate channel models based on their applications, classification, features, advantages, and limitations.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Wang ◽  
Bo Ai ◽  
Ke Guan ◽  
David W. Matolak ◽  
Ruisi He ◽  
...  

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.


2021 ◽  
pp. 228-235
Author(s):  
Sarun Duangsuwan ◽  

A challenge swarm unmanned aerial vehicles (swarm UAVs)-based wireless communication systems have been focused on channel modeling in various environments. In this paper, we present the characterized path loss air-to-air (A2A) channel modeling-based measurement and prediction model. The channel model was considered using A2A Two-Ray (A2AT-R) extended path loss modeling. The prediction model was considered using an artificial neural network (ANN) algorithm to train the measured dataset. To evaluate the measurement result, path loss models between the A2AT-R model and the prediction model are shown. We show that the prediction model using ANN is optimal to train the measured data for the A2A channel model. To discuss the result, the parametric prediction errors such as mean absolute error (MAE), root mean square error (RMSE), and R-square (R2), are performed.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jinsong Gui ◽  
Fujian Cai

The unmanned aerial vehicle- (UAV-) assisted sub-6 GHz disaster relief networks cannot meet high-speed transmission requirements. In this paper, the millimeter wave (mmWave) frequency band is combined with the sub-6 GHz frequency band to build a high-speed UAV-assisted disaster relief network. However, the high propagation path loss of mmWave signals usually needs to be compensated by beamforming, where the ground-facing beam of each UAV is the desired receiving beam of ground user information. The different channels need to be allocated to a single UAV so that this kind of beam can be used simultaneously by different ground users to communicate with this UAV. Also, the other UAVs should reuse these channels as much as possible to save spectrum resources. In this paper, the beamforming training (BFT) mechanism is firstly used to obtain the signal-to-noise ratio (SNR) values of all possible links between ground terminals and UAVs, which are used to estimate these links’ energy efficiency. Then, an interference graph construction algorithm is proposed to identify the links that cannot be used simultaneously in the same channel according to the system energy efficiency. Finally, an iterative channel allocation algorithm is designed to allocate new channels to eliminate the edges of the interference graph, so that the links obtained by the BFT process can be used simultaneously as much as possible under the constraint of the number of channels. The simulation results show that our proposed scheme can achieve the shorter average convergence time, the higher data rate (or the lower data loss rate), and the higher energy efficiency.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Junyi Yu ◽  
Wei Chen ◽  
Kun Yang ◽  
Changzhen Li ◽  
Fang Li ◽  
...  

In this paper, a propagation path loss model for inland river is proposed by three improvements compared with the Round Earth Loss (REL) model for open-sea environment. Specifically, parameters optimization uses Okumura-Hata model in dB scale to replace the equation transformed from the free space loss in REL model; secondly, diffraction loss caused by the obstacles (e.g., large buildings, bridges, or some other facilities near the river bank) is also taken into account; mixed-path methodology as another improvement is used for Inland River (IR) model because the actual propagation environment between transmitter (TX) antenna and receiver (RX) antenna contains both land part and water part. The paper presents a set of 1.4 GHz measurements conducted along the Yangtze River in Wuhan. According to the comparison between path loss models and experimental results, IR model shows a good matching degree. After that, Root Mean Square Error (RMSE), Grey Relation Grade and Mean Absolute Percentage Error (GRG-MAPE), Pearson Correlation Coefficient, and Mean Absolute Percentage Error (PCC-MAPE) are employed to implement quantitative analysis. The results prove that IR model with consideration of mixed path and deterministic information is more accurate than other classic empirical propagation models for these scenarios.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Mustafa Alper Akkaş ◽  
Radosveta Sokullu

Wireless underground sensor networks (WUSNs) are networks of sensor nodes operating below the ground surface, which are envisioned to provide real-time monitoring capabilities in the complex underground environments consisting of soil, water, oil, and other components. In this paper, we investigate the possibilities and limitations of using WUSNs for increasing the efficiency of oil recovery processes. To realize this, millimeter scale sensor nodes with antennas at the same scale should be deployed in the confined oil reservoir fractures. This necessitates the sensor nodes to be operating in the terahertz (THz) range and the main challenge is establishing reliable underground communication despite the hostile environment which does not allow the direct use of most existing wireless solutions. The major problems are extremely high path loss, small communication range, and high dynamics of the electromagnetic (EM) waves when penetrating through soil, sand, and water and through the very specific crude oil medium. The objective of the paper is to address these issues in order to propose a novel communication channel model considering the propagation properties of terahertz EM waves in the complex underground environment of the oil reservoirs and to investigate the feasible transmission distances between nodes for different water-crude-oil-soil-CO2compositions.


Author(s):  
Jianzheng Li ◽  
Fei Li ◽  
Wei Ji ◽  
Yulong Zou ◽  
Chunguo Li

In this paper a three-dimension (3D) multiple-input multiple-output (MIMO) channel model is derived by considering the elevation dimension and the azimuth dimension together. To get a more accurate performance analysis for 3D MIMO channel, both Tx and Rx correlation matrices are derived, respectively, in closed form, which consist of 3D Kronecker channel model. This novel 3D Kronecker channel model is developed for arbitrary antenna arrays with non-isotropic antenna patterns and also for any propagation environment of 3D MIMO systems. In order to quantify the performance of 3D MIMO systems, the capacity in multi-user cases is analyzed. Simulation results validate the proposed 3D Kronecker channel model and study the impact of elevation and azimuth angular spread and that of Rx antenna element spacing on the correlation. The proposed capacity analysis in multi-user cases for 3D MIMO systems is also verified by simulation.


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