Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Distributed Receivers for Extra-Large Scale MIMO Arrays: A Message
  Passing Approach   We study the design of receivers in extra-large scale MIMO (XL-MIMO) systems,
i.e. systems in which the base station is equipped with an antenna array of
extremely large dimensions. While XL-MIMO can significantly increase the
system's spectral efficiency, they present two important challenges. One is the
increased computational cost of the multi-antenna processing. The second is the
variations of user energy distribution over the antenna elements and therefore
spatial non-stationarities in these energy distributions. Such
non-stationarities limit the performance of the system. In this paper, we
propose a distributed receiver for such an XL-MIMO system that can address both
challenges. Based on variational message passing (VMP), We propose a set of
receiver options providing a range of complexity-performance characteristics to
adapt to different requirements. Furthermore, we distribute the processing into
local processing units (LPU), that can perform most of the complex processing
in parallel, before sharing their outcome with a central processing unit (CPU).
Our designs are specifically tailored to exploit the spatial non-stationarities
and require lower computations than linear receivers such as zero-forcing. Our
simulation study, performed with a channel model accounting for the special
characteristics of XL-MIMO channels, confirms the superior performance of our
proposals compared to the state of the art methods.

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The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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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: patt-sol
2
The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int