Terahertz Channel Propagation Phenomena, Measurement Techniques and
Modeling for 6G Wireless Communication Applications: a Survey, Open
Challenges and Future Research Directions
The Terahertz (THz) band (0.1-3.0 THz) spans a great portion of the
Radio Frequency (RF) spectrum that is mostly unoccupied and unregulated.
It is a potential candidate for application in Sixth-Generation (6G)
wireless networks as it has the capabilities of satisfying the high data
rate and capacity requirements of future wireless communication systems.
Profound knowledge of the propagation channel is crucial in
communication systems design which nonetheless, is still at its infancy
as channel modeling at THz frequencies has been mostly limited to
characterizing fixed Point-to-Point (P2P) scenarios up to 300 GHz.
Provided the technology matures enough and models adapt to the
distinctive characteristics of the THz wave, future wireless
communications systems will enable a plethora of new use cases and
applications to be realized in addition to delivering higher spectral
efficiencies that would ultimately enhance the Quality-of-Service (QoS)
to the end user. In this paper, we provide an insight into THz channel
propagation characteristics, measurement capabilities and modeling
methods along with recommendations that will aid in the development of
future models in the THz band. We survey the most recent and important
measurement campaigns and modeling efforts found in literature based on
the use cases and system requirements identified. Finally, we discuss
the challenges and limitations of measurements and modeling at such high
frequencies and contemplate the future research outlook toward realizing
the 6G vision.