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.