This paper presents a comprehensive wideband indoor propagation characterization via real-world experiments at 105.8 GHz with a 4 GHz bandwidth in a lecture hall environment. Utilizing a double-directional channel sounding system with rotating horn antennas, we measure power angular delay profiles (PADPs) at multiple receiver (RX) positions. Our study derives a path loss model, delay characteristics, and angle characteristics, including path loss exponent, root mean square (RMS) delay spread (DS), K-factor, RMS azimuth angle spread of arrival (ASA), and RMS azimuth angle spread of departure (ASD). We compared these results with the 3GPP indoor hotspot (InH) office model (up to 100 GHz), highlighting both similarities and differences in propagation characteristics. Notably, the path loss exponent was found to be 1.38, which is lower than the 1.73 observed in the 3GPP InH-Office LoS model. Moreover, there were positive correlations between the above spread values and transmitter (TX)-RX distance, and negative correlations between K-factor and TX-RX distance, which were not considered in the 3GPP InH-Office LoS model. Furthermore, our analysis revealed a strong negative correlation in RMS ASA vs K-factor and RMS ASD vs K-factor, which are not accounted for in the current 3GPP InH office model. These findings emphasize the need to consider such correlations in accurate propagation models in lecture hall scenarios at the 105 GHz sub-THz band.

This paper comprehensively presents 105 GHz multipath characterizations for indoor short-range communication environments and proposes a stochastic channel generator compatible with the third-generation project partnership (3GPP) standard. Using extensive wideband propagation measurements, we holistically derive the statistical distributions of both largescale parameters (LSPs) and small-scale parameters for various indoor short-range communication environments, such as desktops in conference rooms, corridors, and office rooms. These distributions not only capture the holistic propagation characteristics of this underexplored frequency band in the aforementioned environments but also serve as a complete stochastic model sufficient for developing a multipath channel generator to perform physical layer link-level simulations. The derived parameters are compared with those specified in the incumbent 3GPP stochastic channel model for an indoor hotspot office scenario, highlighting the fact that the cross-correlation between the azimuth angle spread of arrival and the K-factor demonstrates a major difference, requiring model amendments for short-range use cases in this band. Based on these results, we propose a 3GPP-compatible channel generation algorithm tailored for all three indoor short-range communication scenarios at 105 GHz, incorporating the derived statistical distributions. The extensive simulations of channel generation demonstrated consistency with our propagation measurements in terms of intra-cluster subpath characteristics and LSPs, demonstrating the validity of the proposed channel generation algorithm. Our results offer a foundation for accurate link-level simulations in various 105 GHz short-range communication use cases, which is crucial for advancing next-generation wireless communication systems. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.

This study conducts a wideband multi-path propagation measurement at the 95 GHz sub-terahertz band for short-range communication in a conference room desktop scenario. Regardless of the fact that the current 3rd generation partnership (3GPP) stochastic channel model (SCM) targets the frequency up to 100 GHz for various scenarios, neither detailed measurements at the 95 GHz band nor a compatible channel modeling/generation framework for indoor short-range communication scenarios have been conducted. To fill these voids, based on a real-world measurement at 95 GHz with a bandwidth of 4 GHz, this study analyzes the multi-path propagation characteristics and yields the following insights for developing a 3GPP SCM-compatible channel generation framework at this band. First, the exponential power decay with delay time and quasi-uniform azimuth angles of arrival (AAoAs) are observed, which should be revisited to develop a channel generation framework. Secondly, distribution models for root mean squared (RMS) delay/AAoA spreads and omnidirectional path loss model are derived, which serves as a foundation for developing a channel generation framework at this band. Moreover, these established models are compared with the recently conducted measurement results at the 60 GHz band in the same scenario, shedding light on the hypothesis that the models for these parameters at the 60 GHz can be generalized for the 95 GHz band. “© 2024 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Published Version:10.1109/WCNC57260.2024.10571036

This paper performs a first wideband indoor channel measurement at the 105 GHz sub-terahertz (sub-THz) band and analyzes the multipath characteristics in terms of the omnidirectional path-loss and angular characteristics. The measurement campaigns with the 4 GHz bandwidth are performed focusing on indoor short-range communication scenarios in a conference room, corridor, and office room, which have been considered in the primary 60 GHz communication systems standardized by the IEEE 802.15.3c/11ad. Moreover, to draw full understanding to scale the 60 GHz indoor channel models and 60 GHz system designs for the 105 GHz band, we also conduct 60 GHz channel measurements in the same environment with few modifications in the channel-sounding system and performed the comparison between these two bands. Based on these measurements, we demonstrate the affinity that exists between 105 GHz and 60 GHz bands in terms of path loss exponent and angular characteristics of multipath components, shedding light on the hypothesis that several system designs of the 60 GHz communication systems (e.g., beam switching for non-line-of sight conditions) can be applied to the 105 GHz sub-THz communication systems. © 2023 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.