Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An Efficient Precoder Design for Multiuser MIMO Cognitive Radio Networks
  with Interference Constraints   We consider a linear precoder design for an underlay cognitive radio
multiple-input multiple-output broadcast channel, where the secondary system
consisting of a secondary base-station (BS) and a group of secondary users
(SUs) is allowed to share the same spectrum with the primary system. All the
transceivers are equipped with multiple antennas, each of which has its own
maximum power constraint. Assuming zero-forcing method to eliminate the
multiuser interference, we study the sum rate maximization problem for the
secondary system subject to both per-antenna power constraints at the secondary
BS and the interference power constraints at the primary users. The problem of
interest differs from the ones studied previously that often assumed a sum
power constraint and/or single antenna employed at either both the primary and
secondary receivers or the primary receivers. To develop an efficient numerical
algorithm, we first invoke the rank relaxation method to transform the
considered problem into a convex-concave problem based on a downlink-uplink
result. We then propose a barrier interior-point method to solve the resulting
saddle point problem. In particular, in each iteration of the proposed method
we find the Newton step by solving a system of discrete-time Sylvester
equations, which help reduce the complexity significantly, compared to the
conventional method. Simulation results are provided to demonstrate fast
convergence and effectiveness of the proposed algorithm.

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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: hep-ph
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: q-bio
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: econ