Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Robustness of Massive MIMO Systems Against Passive Eavesdropping
  under Antenna Selection   In massive MIMO wiretap settings, the base station can significantly suppress
eavesdroppers by narrow beamforming toward legitimate terminals. Numerical
investigations show that by this approach, secrecy is obtained at no
significant cost. We call this property of massive MIMO systems `secrecy for
free' and show that it not only holds when all the transmit antennas at the
base station are employed, but also when only a single antenna is set active.
Using linear precoding, the information leakage to the eavesdroppers can be
sufficiently diminished, when the total number of available transmit antennas
at the base station grows large, even when only a fixed number of them are
selected. This result indicates that passive eavesdropping has no significant
impact on massive MIMO systems, regardless of the number of active transmit
antennas.

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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph