Millimeter Wave and Sub-THz Indoor Radio Propagation Channel Measurements, Models, and Comparisons in an Office Environment

This letter provides a comparison of indoor radio propagation measurements and corresponding channel statistics at 28, 73, and 140 GHz, based on extensive measurements from 2014-2020 in an indoor office environment. Side-by-side comparisons of propagation characteristics (e.g., large-scale path loss and multipath time dispersion) across a wide range of frequencies from the low millimeter wave band of 28 GHz to the sub-THz band of 140 GHz illustrate the key similarities and differences in indoor wireless channels. The measurements and models show remarkably similar path loss exponents over frequencies in both line-of-sight (LOS) and non-LOS (NLOS) scenarios, when using a one meter free space reference distance, while the multipath time dispersion becomes smaller at higher frequencies. The 3GPP indoor channel model overestimates the large-scale path loss and has unrealistic large numbers of clusters and multipath components per cluster compared to the measured channel statistics in this letter.

Automated summary

This study compares indoor radio propagation measurements and channel statistics at 28, 73, and 140 GHz in an indoor office environment, revealing similarities and differences in propagation characteristics across different frequencies. The research findings show that path loss exponents remain similar across frequencies when using a one meter free space reference distance, while multipath time dispersion decreases at higher frequencies. Additionally, the 3GPP indoor channel model is found to overestimate path loss and have unrealistic numbers of clusters and multipath components per cluster compared to measured channel statistics.