In this paper, we demonstrate for the first time 100 Gbit/s real-time THz-wireless data transmission at a carrier frequency of 300 GHz using a single broadband real-time modem originally designed for 2×2 Polarization-MIMO digital-coherent fiber-optical transmission. As a reference, the performance of the 50-cm long, LoS, spatially multiplexed (x2) wireless link is also evaluated using offline DSP algorithms optimized for the THz setup. During the real-time operation of the system, we have recorded the pre-FEC BER over 100 hours of continuous operation to demonstrate the stability of the system.