Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Secure Transmission for Intelligent Reflecting Surface-Assisted mmWave
  and Terahertz Systems   This letter focuses on the secure transmission for an intelligent reflecting
surface (IRS)-assisted millimeter-wave (mmWave) and terahertz (THz) systems, in
which a base station (BS) communicates with its destination via an IRS, in the
presence of a passive eavesdropper. To maximize the system secrecy rate, the
transmit beamforming at the BS and the reflecting matrix at the IRS are jointly
optimized with transmit power and discrete phase-shift constraints. It is first
proved that the beamforming design is independent of the phase shift design
under the rank-one channel assumption. The formulated non-convex problem is
then converted into two subproblems, which are solved alternatively.
Specifically, the closed-form solution of transmit beamforming at the BS is
derived, and the semidefinite programming (SDP)-based method and element-wise
block coordinate descent (BCD)-based method are proposed to design the
reflecting matrix. The complexity of our proposed methods is analyzed
theoretically. Simulation results reveal that the proposed IRS-assisted secure
strategy can significantly boost the secrecy rate performance, regardless of
eavesdropper's locations (near or blocking the confidential beam).

24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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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: adap-org
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con