Comparison of Indoor Propagation Channels at 28 GHz and 140 GHz Bands

In this paper, a comparison between the measured 28 GHz and 140 GHz channels in an entrance hall is presented. The path loss, angular spread, delay spread, and composite power angular spectrum (PAS) are evaluated and compared with reference indoor channels in an office, existing model, and shopping mall. The existing model and office path loss curves align with the path loss of line-of-sight (LOS) and non-LOS (NLOS) links, respectively. When using the full dynamic range, the angular spread does not change with frequency, while the delay spread decreases with frequency in the entrance hall. The differences in angular spread and delay spread vary between the entrance hall and other indoor environments due to differences in layout. The composite PAS at both bands are similar for both LOS and NLOS links. The channels have larger angular and delay spread at 140 GHz than 28 GHz when the same dynamic range is used.