Terahertz communication for 6G: architectures, technologies and challenges

With the increasing demand for transmission rate of wireless network, the sixth generation of mobile communication system (6G) will evolve to the terahertz frequency band. It is urgent to solve the problem of large-capacity terahertz wireless communication, so as to develop terahertz broadband spectrum resources and simultaneously achieve 6G performance targets such as ultra-high transmission rate, ultra-high spectrum efficiency, ultra-high energy efficiency, etc. This paper mainly introduces the domestic and international development status of terahertz communication, the architecture and classification of terahertz wireless communication system and large-capacity terahertz wireless communication technology, and summarizes the research progress and bottleneck problems of large-capacity terahertz wireless communication, including terahertz signal transceiving and communication system architectures, efficient modulation and processing of broadband signal, wireless and fiber fusion, hardware experimental systems, etc. Based on the analysis of research status, the future development trends and challenges of terahertz wireless communication for 6G are posted.