Channel characterization and analysis for indoor non-line-of-sight ultraviolet communications

Current research on ultraviolet (UV) channel modeling has predominantly emphasized outdoor environments, whereas indoor scenarios remain comparatively underexplored. To address this research disparity, we conduct a systematic investigation of UV propagation characteristics in indoor environments. First, we develop a non-line-of-sight channel model for obstruction-free indoor UV scenarios, where the received pulse energy incorporates contributions from both air scattering and multisurface reflections off walls, the ceiling, and the floor. Building upon this foundation, we extend the modeling framework to obstructed indoor UV scenarios by integrating spatial parameters of obstacles to achieve enhanced fidelity with practical indoor communication configurations. Simulation results demonstrate that the path loss curves obtained by the proposed model agree well with those obtained by the reflection-assisted Monte Carlo photon-tracking model. Moreover, we investigate the indoor UV path loss, scattered energy, and reflected energy dependencies on important variables, including communication range, transceiver elevation angles, receiver field-of-view angle, and obstacle parameters.