Sub-Terahertz MassiveMIMO Channel Sounder for 6G Mobile Communication Systems

6G mobile communications will require extremely high-speed data rates exceeding 100 Gbps using sub-terahertz (THz) bands. Sub-THz bands have extremely short wavelengths, and channel characteristics are affected by objects and people surrounding mobile stations. Therefore, we have developed a sub-THz Massive MIMO channel sounder using 896 antenna elements. This channel sounder offers a high time-spatial channel resolution. It can analyze the number of arriving paths with lower received power in realtime, which can contribute to constructing an accurate 6G channel model and feasible 6G system using sub-THz bands. In this paper, we introduce a newly developed sub-THz MassiveMIMO channel sounder and demonstrate the system performance in an outdoor environment.