Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 3D Placement and Orientation of mmWave-based UAVs for Guaranteed LoS
  Coverage   Unmanned aerial vehicles (UAVs), as aerial base stations, are a promising
solution for providing wireless communications, thanks to their high
flexibility and autonomy. Moreover, emerging services, such as extended
reality, require high-capacity communications. To achieve this, millimeter wave
(mmWave), and recently, terahertz bands have been considered for UAV
communications. However, communication at these high frequencies requires a
line-of-sight (LoS) to the terminals, which may be located in 3D space and may
have extremely limited direct-line-of-view (LoV) due to blocking objects, like
buildings and trees. In this paper, we investigate the problem of determining
3D placement and orientation of UAVs such that users have guaranteed LoS
coverage by at least one UAV and the signal-to-noise ratio (SNR) between the
UAV-user pairs are maximized. We formulate the problem as an integer linear
programming(ILP) problem and prove its NP-hardness. Next, we propose a
low-complexity geometry-based greedy algorithm to solve the problem
efficiently. Our simulation results show that the proposed algorithm (almost)
always guarantees LoS coverage to all users in all considered simulation
settings.

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The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: econ
37
The categories of this paper are: supr-con