Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy Efficient Precoder in Multi-User MIMO Systems with Imperfect
  Channel State Information   This article is on the energy efficient precoder design in multi-user
multiple-input-multiple-output (MU-MIMO) systems which is also robust with
respect to the imperfect channel state information (CSI) at the transmitters.
In other words, we design the precoder matrix associated with each transmitter
to maximize the general energy efficiency of the network. We investigate the
problem in two conventional cases. The first case considers the statistical
characterization for the channel estimation error that leads to a quadratically
constrained quadratic program (QCQP) with a semi-closed-form solution. Then, we
turn our attention to the case which considers only the uncertainty region for
the channel estimation error; this case eventually results in a semi-definite
program (SDP).

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The categories of this paper are: cond-mat
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The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
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The categories of this paper are: eess
3
The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
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The categories of this paper are: nlin
28
The categories of this paper are: alg-geom