Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectrum Sharing in Cognitive Radio with Quantized Channel Information   We consider a wideband spectrum sharing system where a secondary user can
share a number of orthogonal frequency bands where each band is licensed to an
individual primary user. We address the problem of optimum secondary transmit
power allocation for its ergodic capacity maximization subject to an average
sum (across the bands) transmit power constraint and individual average
interference constraints on the primary users. The major contribution of our
work lies in considering quantized channel state information (CSI)(for the
vector channel space consisting of all secondary-to-secondary and
secondary-to-primary channels) at the secondary transmitter. It is assumed that
a band manager or a cognitive radio service provider has access to the full CSI
information from the secondary and primary receivers and designs (offline) an
optimal power codebook based on the statistical information (channel
distributions) of the channels and feeds back the index of the codebook to the
secondary transmitter for every channel realization in real-time, via a
delay-free noiseless limited feedback channel. A modified Generalized
Lloyds-type algorithm (GLA) is designed for deriving the optimal power
codebook. An approximate quantized power allocation (AQPA) algorithm is also
presented, that performs very close to its GLA based counterpart for large
number of feedback bits and is significantly faster. We also present an
extension of the modified GLA based quantized power codebook design algorithm
for the case when the feedback channel is noisy. Numerical studies illustrate
that with only 3-4 bits of feedback, the modified GLA based algorithms provide
secondary ergodic capacity very close to that achieved by full CSI and with
only as little as 4 bits of feedback, AQPA provides a comparable performance,
thus making it an attractive choice for practical implementation.

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The categories of this paper are: astro-ph
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat