Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis of Energy Efficiency in Fading Channels under QoS Constraints   Energy efficiency in fading channels in the presence of Quality of Service
(QoS) constraints is studied. Effective capacity, which provides the maximum
arrival rate that a wireless channel can sustain while satisfying statistical
QoS constraints, is considered. Spectral efficiency--bit energy tradeoff is
analyzed in the low-power and wideband regimes by employing the effective
capacity formulation, rather than the Shannon capacity. Through this analysis,
energy requirements under QoS constraints are identified. The analysis is
conducted under two assumptions: perfect channel side information (CSI)
available only at the receiver and perfect CSI available at both the receiver
and transmitter. In particular, it is shown in the low-power regime that the
minimum bit energy required under QoS constraints is the same as that attained
when there are no such limitations. However, this performance is achieved as
the transmitted power vanishes. Through the wideband slope analysis, the
increased energy requirements at low but nonzero power levels in the presence
of QoS constraints are determined. A similar analysis is also conducted in the
wideband regime, and minimum bit energy and wideband slope expressions are
obtained. In this regime, the required bit energy levels are found to be
strictly greater than those achieved when Shannon capacity is considered.
Overall, a characterization of the energy-bandwidth-delay tradeoff is provided.

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The categories of this paper are: nlin
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The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: physics
16
The categories of this paper are: stat
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The categories of this paper are: gr-qc
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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: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ph