Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Joint Transmit Power and Placement Optimization for URLLC-enabled UAV
  Relay Systems   This letter considers an unmanned aerial vehicle (UAV)-enabled relay
communication system for delivering latency-critical messages with ultra-high
reliability, where the relay is operating under amplifier-and-forward (AF)
mode. We aim to jointly optimize the UAV location and power to minimize
decoding error probability while guaranteeing the latency constraints. Both the
free-space channel model and three-dimensional (3-D) channel model are
considered. For the first model, we propose a low-complexity iterative
algorithm to solve the problem, while globally optimal solution is derived for
the case when the signal-to-noise ratio (SNR) is extremely high. For the second
model, we also propose a low-complexity iterative algorithm to solve the
problem. Simulation results confirm the performance advantages of our proposed
algorithms.

29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom