The ever-increasing capacity demand (up to Tbps) in wireless connectivity is supposed can be satisfied by using terahertz frequency band ranging from 100 GHz to 10 THz. This has been proved over short channel distances in laboratory with high order modulation schemes (such as QPSK, QAM) employed. However, in outdoor adverse weathers, investigations on channel performance are not enough due to difficulties in outdoor measurements, and then more concentrations are still required. In this article, we report performance of terahertz channels in emulated falling rain in our lab by utilizing a broadband-pulsed terahertz channel and a 16-QAM modulated data stream. We observe that, the variability of raindrop size distribution is a major source of uncertainty in theoretical precipitation. We also find that the channel degradation in falling rain is mainly due to power attenuation, instead of phase dispersion which is negligible in our measurement.
