Online search for UAV relay placement for free-space optical communication under shadowing
Unmanned aerial vehicle (UAV) relaying is promising to overcome the challenge of signal blockage in free-space optical (FSO) communications for users in dense urban area. Existing works on UAV relay placement are mostly based on simplified line-of-sight (LOS) channel models or probabilistic channel...
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| Format: | Article |
| Language: | English |
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Tsinghua University Press
2023-03-01
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| Series: | Intelligent and Converged Networks |
| Subjects: | |
| Online Access: | https://www.sciopen.com/article/10.23919/ICN.2023.0003 |
| _version_ | 1797801060424744960 |
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| author | Yuanshuai Zheng Yinjun Wang Junting Chen |
| author_facet | Yuanshuai Zheng Yinjun Wang Junting Chen |
| author_sort | Yuanshuai Zheng |
| collection | DOAJ |
| description | Unmanned aerial vehicle (UAV) relaying is promising to overcome the challenge of signal blockage in free-space optical (FSO) communications for users in dense urban area. Existing works on UAV relay placement are mostly based on simplified line-of-sight (LOS) channel models or probabilistic channel models, and thus fail to capture the actual LOS status of the optical communication link. By contrast, this paper studies three-dimensional (3D) online placement for a UAV to construct relay links to two ground users in deep shadow with LOS guarantees. By analyzing the properties of the UAV relay placement problem, it is found that searching on a plane that approximates the equipotential surface can achieve a good performance and complexity trade-off for a good placement of the UAV relay in 3D. Based on these insights, a two-stage online search algorithm on an equipotential plane (TOSEP) is developed for a special case where the equipotential surface turns out to be an equipotential plane. For the general case, a strategy called gradient projected online search algorithm on an approximated equipotential plane (GOSAEP) is developed, which approximates the equipotential surface with a perpendicular plane using the gradient projection method. Numerical experiments are conducted over a real-world city topology, and it is shown that the GOSAEP achieves over 95% of the performance of the exhaustive 3D search scheme within a 300-m search length. |
| first_indexed | 2024-03-13T04:44:40Z |
| format | Article |
| id | doaj.art-9ef29e40130546238c5d58efe23990e4 |
| institution | Directory Open Access Journal |
| issn | 2708-6240 |
| language | English |
| last_indexed | 2024-03-13T04:44:40Z |
| publishDate | 2023-03-01 |
| publisher | Tsinghua University Press |
| record_format | Article |
| series | Intelligent and Converged Networks |
| spelling | doaj.art-9ef29e40130546238c5d58efe23990e42023-06-19T04:00:36ZengTsinghua University PressIntelligent and Converged Networks2708-62402023-03-0141284010.23919/ICN.2023.0003Online search for UAV relay placement for free-space optical communication under shadowingYuanshuai Zheng0Yinjun Wang1Junting Chen2School of Science and Engineering and the Future Network of Intelligence Institute (FNii), The Chinese University of Hong Kong, Shenzhen 518172, ChinaSchool of Science and Engineering and the Future Network of Intelligence Institute (FNii), The Chinese University of Hong Kong, Shenzhen 518172, ChinaSchool of Science and Engineering and the Future Network of Intelligence Institute (FNii), The Chinese University of Hong Kong, Shenzhen 518172, ChinaUnmanned aerial vehicle (UAV) relaying is promising to overcome the challenge of signal blockage in free-space optical (FSO) communications for users in dense urban area. Existing works on UAV relay placement are mostly based on simplified line-of-sight (LOS) channel models or probabilistic channel models, and thus fail to capture the actual LOS status of the optical communication link. By contrast, this paper studies three-dimensional (3D) online placement for a UAV to construct relay links to two ground users in deep shadow with LOS guarantees. By analyzing the properties of the UAV relay placement problem, it is found that searching on a plane that approximates the equipotential surface can achieve a good performance and complexity trade-off for a good placement of the UAV relay in 3D. Based on these insights, a two-stage online search algorithm on an equipotential plane (TOSEP) is developed for a special case where the equipotential surface turns out to be an equipotential plane. For the general case, a strategy called gradient projected online search algorithm on an approximated equipotential plane (GOSAEP) is developed, which approximates the equipotential surface with a perpendicular plane using the gradient projection method. Numerical experiments are conducted over a real-world city topology, and it is shown that the GOSAEP achieves over 95% of the performance of the exhaustive 3D search scheme within a 300-m search length.https://www.sciopen.com/article/10.23919/ICN.2023.0003free-space optical communicationrelay communicationunmanned aerial vehicle (uav)trajectory designcapacity maximization |
| spellingShingle | Yuanshuai Zheng Yinjun Wang Junting Chen Online search for UAV relay placement for free-space optical communication under shadowing Intelligent and Converged Networks free-space optical communication relay communication unmanned aerial vehicle (uav) trajectory design capacity maximization |
| title | Online search for UAV relay placement for free-space optical communication under shadowing |
| title_full | Online search for UAV relay placement for free-space optical communication under shadowing |
| title_fullStr | Online search for UAV relay placement for free-space optical communication under shadowing |
| title_full_unstemmed | Online search for UAV relay placement for free-space optical communication under shadowing |
| title_short | Online search for UAV relay placement for free-space optical communication under shadowing |
| title_sort | online search for uav relay placement for free space optical communication under shadowing |
| topic | free-space optical communication relay communication unmanned aerial vehicle (uav) trajectory design capacity maximization |
| url | https://www.sciopen.com/article/10.23919/ICN.2023.0003 |
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