Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Initial Access for Millimeter-Wave and Terahertz Communications with
  Hybrid Beamforming   In order to achieve terabits-per-second (Tbps) data rates in the
sixth-generation (6G) mobile system, wireless communications are required to
exploit the abundant spectrum in the millimeter-wave (mmWave) and terahertz
(THz) bands. However, high-frequency transmission heavily relies on high
beamforming gain to compensate for severe propagation loss. A beam-based system
faces a barrier in the process of initial access, where a base station must
broadcast synchronization signals and system information to all users within
its coverage. Hence, this paper proposes a novel omnidirectional broadcasting
scheme for mmWave and THz systems with hybrid beamforming. It provides an
instantaneously equal gain over all directions by forming complementary beams
over sub-arrays. Numerical results verify that it can achieve omnidirectional
coverage with a performance that remarkably outperforms the previous scheme.

8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat