Integration and Validation of LEO NTN-TDL Channel Models in OpenAirInterface5G

This paper presents the implementation and validation of 3GPP TR 38.811-aligned Non-Terrestrial Network tapped-delay-line (NTN-TDL) channel models in the OpenAirInterface5G (OAI) radio-frequency simulator (RFsim) for Low Earth Orbit (LEO) satellite scenarios. The proposed implementation supports standardized NTN-TDL A, B, C, and D multipath profiles together with key LEO channel dynamics, including time-varying propagation delay, bulk Doppler evolution, elevation-dependent delay-spread, and per-tap Doppler extension. The implementation is validated through code-level consistency checks and controlled OAI RFsim experiments designed for reproducibility. The results confirm correct tap delays, normalized powers, and Ricean (K)-factors against TR 38.811 reference tables. They further verify coherent delay and Doppler evolution, phase continuity across block updates, environment-dependent delay-spread execution across dense urban, urban, suburban, and rural settings, and PHY-level execution across NTN-TDL A–D profiles. Performance measurements further quantify the runtime and memory overhead of the optional per-tap extension. The implementation provides a reproducible OAI-based realization of LEO NTN-TDL models for channel-level and PHY experimentation, supporting future studies of link adaptation and robustness under realistic LEO channel dynamics.

IEEE International Conference on Advanced Networks and Telecommunications Systems (ANTS 2026)