Recent Advances of Propagation Channel Research for 6G Wireless Communication Systems

Channel is the primary building block of wireless
communication system between the transmitter and receivers.
Measuring, characterizing, and modeling channels are of significant
importance for network modeling, system deployment, and
theoretical analysis of communication systems. Next-generation
networks such as sixth-generation (6G) will bring new enabling
technologies (THz), multiple mobilities (high-speed train (HST),
UAV trajectory), and architectures (3D network, integrated
terrestrial-non terrestrial network) which ought to cater to
channel propagation characteristics. Accurate channel models
that combine different technologies and disciplines can capture
these channel characteristics play a critical role in designing
and testing the future 6G system. In this article, we overview
the characteristics, measurement, and modeling of 6G wireless
channels. Also, we provide a summary of recent advances
in channel research of 6G. Finally, we outline the research
challenges, open issues, and future direction of channel models
and characteristics in 6G wireless communications.