Modern wireless communication systems (WCS) based on the use of ultrawideband signals (UWB) operate in the 3.1–10.6 GHz band and have an coverage range no more than a few tens of meters, which is due to the level limitation of the radiation power spectral density of the signal not higher than −41.3 dBm/MHz, established by the USA FCC to ensure electromagnetic compatibility with other radio systems. To increase the range of such wireless systems, a number of literature sources propose the usage of radio frequency spectrum free bands, in particular the frequency band above 100 GHz, which is called terahertz (THz). Therefore, this paper proposes a THz WCS simulation model of the 110…170 GHz band based on the pulsed UWB signals application with a detailed description of its main blocks, which is implemented in the NI AWR software environment. The developed model shows the theoretical possibility of data stream transmission (for example, full HD video) with 100 Mbps rate between corresponding stations located in the line-of-sight at a distance of approximately 1 km. The model shows that the main type of THz UWB signal distortion, which causes a “ringing” of the signal in the time domain between two adjacent transmitted UWB pulses, is caused by the limitation of the frequency bandwidth to the range of 110…170 GHz in the bandpass filters of the transmitting and receiving parts. The presented article may be useful to developers of WCS in the THz frequency band.