Ambit-Process Based Channel Model for Urban Microcellular Communication at 140 GHz.

The design and development of sub-Terahertz (THz) communication systems entail the need for new channel models that can precisely predict channel characteristics at such frequencies (>100 GHz) in outdoor and dynamic environments. This work proposes a novel hybrid-stochastic ultra-wideband channel model for sub-THz bands, developed within the framework of a class of spatio-temporal stochastic processes called ambit-process. The proposed model is capable of supporting bandwidths of upto 10 GHz. The spatio-temporal evolution of the ambit framework allows for a reasonably accurate and tractable characterization of the fading statistics and multipath propagation of a cellular channel with good spatial consistency. We leverage a recently proposed low-complexity ambit-process based channel simulation algorithm with necessary modifications to study key features of the outdoor sub-THz channel like associated diffused scattering, molecular absorption, spatio-temporal correlations, and consistency between the time-evolving delay and Doppler of the multipaths. Simulation results on path loss, delay spread, and channel correlation indicate that the ambit model accurately captures the typicalities of an urban microcellular sub-THz channel and agrees well with the measurement results reported in the literature.