Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-complexity Robust Optimization for an IRS-assisted Multi-Cell
  Network   The impacts of channel estimation errors, inter-cell interference, phase
adjustment cost, and computation cost on an intelligent reflecting surface
(IRS)-assisted system are severe in practice but have been ignored for
simplicity in most existing works. In this paper, we investigate a
multi-antenna base station (BS) serving a single-antenna user with the help of
a multi-element IRS in the presence of channel estimation errors and inter-cell
interference. We consider imperfect channel state information (CSI) at the BS,
i.e., imperfect CSIT, and focus on the robust optimization of the BS's
instantaneous CSI-adaptive beamforming and the IRS's quasi-static phase shifts.
First, we formulate the robust optimization of the BS's instantaneous channel
state information (CSI)-adaptive beamforming and IRS's quasi-static phase
shifts for the ergodic rate maximization as a very challenging two-timescale
stochastic non-convex problem. Then, we obtain a closed-form beamformer for any
given phase shifts and a more tractable single-timescale stochastic non-convex
problem only for phase shifts. Next, we propose a low-complexity stochastic
algorithm to obtain quasi-static phase shifts which correspond to a KKT point
of the single-timescale stochastic problem. It is worth noting that the
proposed method offers a closed-form robust instantaneous CSI-adaptive
beamforming design that can promptly adapt to rapid CSI changes over slots and
a robust quasi-static phase shift design of low computation and phase
adjustment costs in the presence of channel estimation errors and inter-cell
interference. Finally, numerical results demonstrate the notable gains of the
proposed robust joint design over existing ones and reveal the practical values
of the proposed solutions.

35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess