# Ray-Optics Simulations of Outdoor-to-Indoor Multipath Channels at 4 and 14 GHz

arXiv: https://arxiv.org/abs/2210.03159 · HTML: https://mlsanity.com/paper/2210.03159/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 6 Oct 2022.

## Built on by (most cited first, 2 of 2)

- [Differentiable High-Performance Ray Tracing-Based Simulation of Radio Propagation with Point Clouds](https://mlsanity.com/paper/2507.04021/) (2025)
- [Differentiable Ray Tracing with Gaussians for Unified Radio Propagation Simulation and View Synthesis](https://mlsanity.com/paper/2605.07781/) (2026)

## Abstract (arXiv)

Radio wave propagation simulations based on the ray-optical approximation have been widely adopted in coverage analysis for a range of situations, including the outdoor-to-indoor scenario. This work presents O2I ray-tracing simulations utilizing a complete office building floor plan in the form of a laser-scanned point cloud. The simulated radio channels are compared to their measured counterparts at 4 and 14 GHz in terms of path loss and delay and angular spreads. Validation of channel simulations for the O2I case is rare, and so far non-existent for above-6~GHz bands. This work reveals the importance of a floor plan model in accurately simulating the channel; it is confirmed that path loss can be replicated with a simple interior path loss model in place of a detailed building interior model, but neglecting to model the interior results in high delay and angular spread errors. By modeling the interior, the ray-tracing simulations achieve relative mean error of under 10% for delay and angular spreads. Finally, effects of multi-layer insulating window on propagation simulations are reported. Noticeable variation of the penetration loss on a small change of the incident angle of a propagation path causes large changes in estimated coverage.