Lessons Learned from a Decade of THz Channel Sounding.

In the last decade, the community has gathered wide-ranging knowledge on wireless THz channels. Becoming a relevant key factor within the next generation of mobile systems, this knowledge impacts the system and algorithm design in many areas. In this article, state-of-the-art channel sounding equipment is presented, and application-oriented methodologies for channel measurements are discussed considering the demands of system designers and the actual capabilities of the measurement equipment. We highlight application-oriented scenarios for THz communication and the specific environmental features of the radio channel. Analyzing the scenarios and relevant insights for wireless THz system development, we illustrate the influence of multipath propagation at THz frequencies and address the impact on wireless THz system design.