  Due to availability of large spectrum chunks, the sub-TeraHertz (subTHz)
frequency band can support Ultra-WideBand (UWB) wireless communications, paving
the way for unprecedented increase in the wireless network capacity. This fact
is expected to be the next breakthrough for the upcoming sixth Generation (6G)
standards. However, the technology of subTHz transceivers is not yet mature
enough to apply the advanced signal processing currently being implemented for
millimeter wave wireless communications. In this paper, we consider the Time
Reversal (TR) precoding technique, which provides simple and robust processing
capable to offer highly focalized in time and space UWB waveforms, exploiting
the spatial diversity of wireless channels. We first investigate experimentally
the performance of subTHz TR focusing in complex media inside a leaking
reverberation cavity. We then combine TR with received spatial modulation to
realize data communication using a simple non-coherent receiver with two
antennas. Our results showcase the capability of TR to offer focusing in time
in the order of few nanoseconds and in space in the order of less than 1 mm.
