Channel characterization and performance analysis of unmanned aerial vehicle‐operated communication system with multihop radio frequency–free‐space optical link in dynamic environment

Abstract

Unmanned aerial vehicles (UAVs) have been widely used in wireless communication in recent years and are a promising component of future wireless systems. UAVs are easily deployable and can provide reliable, robust, and costeffective communication to any desired location. However, the performance parameters of UAV cannot attain the desired level due to additional path loss caused by diffraction in non-line of sight (NLOS) propagation during atmospheric turbulence. In this paper, UAV operated communication system with multihop radio frequency (RF)-free-space optical (FSO) link is proposed. In order to provide better network connectivity and coverage, relays which also act as low altitude platform are configured between source and destination. These relays are modeled using RF and FSO technologies and also maintain decode and forward protocol and linear network coding. Based on this setup, communication channel is classified into three segments namely, ground to UAV, UAV to UAV, and UAV to ground channel. Initially, the optimal altitude of UAVs is derived using RF and FSO channel parameters for reliable system performance. The proposed model is verified using Monte Carlo simulation method, and the performance of the model is measured in terms of outage probability and symbol error rate, assuming that coherent detection takes place at receiver which employs M-ary phase shift keying modulation techniques. Numerical results demonstrate that the proposed multihop RF-FSO link outperforms the relevant benchmark schemes for a given signal to noise ratio value. K E Y W O R D S free-space optical (FSO), Monte Carlo simulation, outage probability, symbol error rate (SER), unmanned aerial vehicle (UAV) 1 | INTRODUCTION A rapid evolution has occurred in the field of wireless communication over the years due to which unmanned aerial vehicles (UAVs) found extensive applications in military, commercial, scientific and agricultural sectors. UAVs such as

Estimation of capabilities of an atmospheric non-line-of-sight optical communication channel between UAV and the ground surface

“…The problem of stable communication between the ground surface and an unmanned aerial vehicle (UAV) is a new promising field in development of atmospheric optical communication [1]. Within the framework of this analysis, the following subfield can be separated in development of channels for communication with UAV: (1) wireless radio and optical line-of-sight (LOS) communication between a ground-based object and a satellite using UAV for relaying [2], (2) hybrid wireless radio and optical (LOS) communication between ground-based objects [3], (3) wireless optical LOS communication [4], and (4) wireless optical non-line-of-sight (NLOS) communication in the atmosphere in the UV range [5][6]. NLOS communication with UAVs could potentially have the following applications: (1) communications in urban environments where the line of sight is blocked by buildings, (2) communication in complex terrain, where the line of sight is blocked by trees or uneven ground, (3) multicast communication, when information is received by several subscribers, (4) relaying of signals via UAV to increase the stability of communication and the information transfer rate, (5) organization of continuous communication with an arbitrarily flying UAV.…”

Non-Line-of-Sight Atmospheric Optical Communication in the Visible Wavelength Range between UAV and the Ground Surface

“…(1) Line-of-sight (LOS) wireless communication in the radio and optical ranges between a ground object and a satellite [3][4][5]; (2) LOS hybrid wireless communication in the radio and optical ranges between land and water surface objects [6][7][8][9]; (3) LOS wireless optical communication [10][11][12][13][14][15]; (4) Combined LOS-NLOS wireless optical communication [16][17][18];…”

Maximization of instantaneous transmission rate in unmanned aerial vehicles‐supported self‐organized device‐to‐device network

“…The ABSOLUTE project, based on the Long‐Term Evolution‐Advanced (LTE‐A) aerial base station, has been inaugurated to support the services for disaster relief activities by providing massive coverage and connectivity 6 . Moreover, due to their agility and mobility, the deployment of UAV relays can be beneficial in a zone where constructing cellular and mobile infrastructure is very expensive 7 . Although while UAVs are operating as aerial relays, the link between ground source device to UAV and the link between UAV to destination device influence the network performance.…”