Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy Efficiency Optimization in IRS-Enhanced mmWave Systems with Lens
  Antenna Array   In millimeter wave (mmWave) systems, the advanced lens antenna array can
effectively reduce the radio frequency chains cost. However, the mmWave signal
is still vulnerable to blocking obstacles and suffers from severe path loss. To
address this problem, we propose an intelligent reflect surface (IRS) enhanced
multi-user mmWave communication system with lens antenna array. Moreover, we
attempt to optimize energy efficiency in the proposed system. An energy
efficiency maximization problem is formulated where the transmit beamforming at
base station and the reflect beamforming at IRSs are jointly considered. To
solve this non-convex problem, we propose an algorithm based on the alternating
optimization technique. In the proposed algorithm, the transmit beamforming is
handled by the sequential convex approximation method and the reflect
beamforming is optimized based on the quadratic transform method. Our
simulation results show that the proposed algorithm can achieve significant
energy efficiency improvement under various scenarios.

27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th