Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An Exploration of the Heterogeneous Unsourced MAC   The unsourced MAC model was originally introduced to study the communication
scenario in which a number of devices with low-complexity and low-energy wish
to upload their respective messages to a base station. In the original problem
formulation, all devices communicate using the same information rate. This may
be very inefficient in certain wireless situations with varied channel
conditions, power budgets, and payload requirements at the devices. This paper
extends the original problem setting so as to allow for such variability. More
specifically, we consider the scenario in which devices are clustered into two
classes, possibly with different SNR levels or distinct payload requirements.
In the cluster with higher power,devices transmit using a two-layer
superposition modulation. In the cluster with lower energy, users transmit with
the same base constellation as in the high power cluster. Within each layer,
devices employ the same codebook. At the receiver, signal groupings are
recovered using Approximate Message Passing(AMP), and proceeding from the high
to the low power levels using successive interference cancellation (SIC). This
layered architecture is implemented using Coded Compressed Sensing(CCS) within
every grouping. An outer tree code is employed to stitch fragments together
across times and layers, as needed.This pragmatic approach to heterogeneous CCS
is validated numerically and design guidelines are identified.

14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc