Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spatial Covariance Matrix Reconstruction for DOA Estimation in Hybrid
  Massive MIMO Systems with Multiple Radio Frequency Chains   Multiple signal classification (MUSIC) has been widely applied in
multiple-input multiple-output (MIMO) receivers for direction-of-arrival (DOA)
estimation. To reduce the cost of radio frequency (RF) chains operating at
millimeter-wave bands, hybrid analog-digital structure has been adopted in
massive MIMO transceivers. In this situation, the received signals at the
antennas are unavailable to the digital receiver, and as a consequence, the
spatial covariance matrix (SCM), which is essential in MUSIC algorithm, cannot
be obtained using traditional sample average approach. Based on our previous
work, we propose a novel algorithm for SCM reconstruction in hybrid massive
MIMO systems with multiple RF chains. By switching the analog beamformers to a
group of predetermined DOAs, SCM can be reconstructed through the solutions of
a set of linear equations. In addition, based on insightful analysis on that
linear equations, a low-complexity algorithm, as well as a careful selection of
the predetermined DOAs, will be also presented in this paper. Simulation
results show that the proposed algorithms can reconstruct the SCM accurately so
that MUSIC algorithm can be well used for DOA estimation in hybrid massive MIMO
systems with multiple RF chains.

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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex