Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Massive Connectivity with Massive MIMO-Part I: Device Activity Detection
  and Channel Estimation   This two-part paper considers an uplink massive device communication scenario
in which a large number of devices are connected to a base-station (BS), but
user traffic is sporadic so that in any given coherence interval, only a subset
of users are active. The objective is to quantify the cost of active user
detection and channel estimation and to characterize the overall achievable
rate of a grant-free two-phase access scheme in which device activity detection
and channel estimation are performed jointly using pilot sequences in the first
phase and data is transmitted in the second phase. In order to accommodate a
large number of simultaneously transmitting devices, this paper studies an
asymptotic regime where the BS is equipped with a massive number of antennas.
The main contributions of Part I of this paper are as follows. First, we note
that as a consequence of having a large pool of potentially active devices but
limited coherence time, the pilot sequences cannot all be orthogonal. However,
despite the non-orthogonality, this paper shows that in the asymptotic massive
multiple-input multiple-output (MIMO) regime, both the missed device detection
and the false alarm probabilities for activity detection can always be made to
go to zero by utilizing compressed sensing techniques that exploit sparsity in
the user activity pattern. Part II of this paper further characterizes the
achievable rates using the proposed scheme and quantifies the cost of using
non-orthogonal pilot sequences for channel estimation in achievable rates.

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The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
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The categories of this paper are: econ
12
The categories of this paper are: nucl-th