Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Achievable DoF and User Scaling Law of Opportunistic Interference
  Alignment in 3-Transmitter MIMO Interference Channels   In this paper, we propose opportunistic interference alignment (OIA) schemes
for three-transmitter multiple-input multiple-output (MIMO) interference
channels (ICs). In the proposed OIA, each transmitter has its own user group
and selects a single user who has the most aligned interference signals. The
user dimensions provided by multiple users are exploited to align interfering
signals. Contrary to conventional IA, perfect channel state information of all
channel links is not required at the transmitter, and each user just feeds back
one scalar value to indicate how well the interfering channels are aligned. We
prove that each transmitter can achieve the same degrees of freedom (DoF) as
the interference free case via user selection in our system model that the
number of receive antennas is twice of the number of transmit antennas. Using
the geometric interpretation, we find the required user scaling to obtain an
arbitrary non-zero DoF. Two OIA schemes are proposed and compared with various
user selection schemes in terms of achievable rate/DoF and complexity.

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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci