Analysis of NTN propagation channels for very low earth orbit (VLEO) and LEO satellites' integration with 5G new radio

The integration of satellites and aerial network nodes with the terrestrial fifth-generation (5G) and beyond-5G cellular networks can provide truly global connectivity coverage. The resulting non-terrestrial networks (NTNs) require multi-dimensional enhancements and innovations. Focusing on the NTN propagation channel modelling aspects, this work investigates the impacts of the satellite altitudes, elevation angles and carrier frequencies on the free space path loss, shadow fading, clutter loss and Doppler shifts. The results show that the elevation angle impacts the path loss and Doppler shift significantly. The results also show that the aggregated path losses for very low Earth orbit (VLEO) satellites are lower than those of the low Earth orbit (LEO) satellites due to the lower altitudes of VLEOs. However, the results also show that VLEOs experience higher Doppler shifts than LEOs which have impacts on the channel fading characteristics. The results provide valuable insights on the NTN channels for a balanced tradeoff in system design as VLEOs continue to attract significant interests for NTN deployments.