Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On proportional fairness of uplink spectral efficiency in cell-free
  massive MIMO systems   This paper is concerned with the proportional fairness (PF) of the spectral
efficiency (SE) maximization of uplinks in a cell-free (CF) massive
multiple-input multiple-output (MIMO) system in which a large number of
single-antenna access points (APs) connected to a central processing unit (CPU)
serve many single-antenna users. To detect the user signals, the APs use
matched filters based on the local channel state information while the CPU
deploys receiver filters based on knowledge of channel statistics. We devise
the maximization problem of the SE PF, which maximizes the sum of the logarithm
of the achievable user rates, as a jointly nonconvex optimization problem of
receiver filter coefficients and user power allocation subject to user power
constraints. To handle the challenges associated with the nonconvexity of the
formulated design problem, we develop an iterative algorithm by alternatively
finding optimal filter coefficients at the CPU and transmit powers at the
users. While the filter coefficient design is formulated as a generalized
eigenvalue problem, the power allocation problem is addressed by a gradient
projection (GP) approach. Simulation results show that the SE PF maximization
not only offers approximately the achievable sum rates as compared to the
sum-rate maximization but also provides an improved trade-off between the user
rate fairness and the achievable sum rate.

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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: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: hep-th