  Terahertz (THz) communication and the application of massive multiple-input
multiple-output (MIMO) technology have been proved significant for the sixth
generation (6G) communication systems, and have gained global interests. In
this paper, we employ the shooting and bouncing ray (SBR) method integrated
with acceleration technology to model THz and massive MIMO channel. The results
of ray tracing (RT) simulation in this paper, i.e., angle of departure (AoD),
angle of arrival (AoA), and power delay profile (PDP) under the frequency band
supported by the commercial RT software Wireless Insite (WI) are in agreement
with those produced by WI. Based on the Kirchhoff scattering effect on material
surfaces and atmospheric absorption loss showing at THz frequency band, the
modified propagation models of Fresnel reflection coefficients and free-space
attenuation are consistent with the measured results. For massive MIMO, the
channel capacity and the stochastic power distribution are analyzed. The
results indicate the applicability of SBR method for building deterministic
models of THz and massive MIMO channels with extensive functions and acceptable
accuracy.
