Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of Receive Spatial Diversity on the Degrees of Freedom Region in
  Multi-Cell Random Beamforming   The random beamforming (RBF) scheme, jointly applied with multi-user
diversity based scheduling, is able to achieve virtually interference-free
downlink transmissions with only partial channel state information (CSI)
available at the transmitter. However, the impact of receive spatial diversity
on the rate performance of RBF is not fully characterized yet even in a
single-cell setup. In this paper, we study a multi-cell multiple-input
multiple-output (MIMO) broadcast system with RBF applied at each base station
(BS) and either the minimum-mean-square-error (MMSE), matched filter (MF), or
antenna selection (AS) based spatial receiver employed at each mobile terminal.
We investigate the effect of different spatial diversity receivers on the
achievable sum-rate of multi-cell RBF systems subject to both the intra- and
inter-cell interferences. We first derive closed-form expressions for the
distributions of the receiver signal-to-interference-plus-noise ratio (SINR)
with different spatial diversity techniques, based on which we compare their
rate performances at finite signal-to-noise ratios (SNRs). We then investigate
the asymptotically high-SNR regime and for a tractable analysis assume that the
number of users in each cell scales in a certain order with the per-cell SNR as
SNR goes to infinity. Under this setup, we characterize the degrees of freedom
(DoF) region for multi-cell RBF systems with different types of spatial
receivers, which consists of all the achievable DoF tuples for the individual
sum-rate of all the cells. The DoF region analysis provides a succinct
characterization of the interplays among the receive spatial diversity,
multiuser diversity, spatial multiplexing gain, inter-/intra-cell
interferences, and BSs' collaborative transmission.

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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ph