Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hardware-Aware Beamspace Precoding for All-Digital mmWave Massive
  MU-MIMO   Massive multi-user multiple-input multiple-output (MU-MIMO) wireless systems
operating at millimeter-wave (mmWave) frequencies enable simultaneous wideband
data transmission to a large number of users. In order to reduce the complexity
of MU precoding in all-digital basestation architectures, we propose a
two-stage precoding architecture that first performs precoding using a sparse
matrix in the beamspace domain, followed by an inverse fast Fourier transform
that converts the result to the antenna domain. The sparse precoding matrix
requires a small number of multipliers and enables regular hardware
architectures, which allows the design of hardware-efficient all-digital
precoders. Simulation results demonstrate that our methods approach the
error-rate of conventional Wiener filter precoding with more than 2x reduced
complexity.

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The categories of this paper are: econ
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The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
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The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol