A Time-correlated Channel State Model for 5G New Radio Mobility Studies in LEO Satellite Networks

Low Earth orbit (LEO) satellite networks will play a major role in future broadband communications. To study LEO satellite mobility performance, and guarantee reliable service, accurate channel characterization is necessary. Current models, such as the ones reported by 3GPP and ITU, define channel parameters as a function of elevation angle, frequency and deployment scenario. However, key parameters including the line-of-sight (LOS) probability and the shadow fading do not describe any time component or correlation and, therefore, the movement of the satellite is not captured. This fact might result in unrealistic changes of the LOS/NLOS states hampering the radio mobility studies for 5G-based LEO satellite networks. In this paper, we present a Markov-based channel state model that takes into consideration the time correlations of the LOS variations along the satellite's orbit. The proposed model is based on ray-tracing measurements of suburban and dense urban scenarios and it can accurately reflect the behaviour of the channel state variations of those scenarios, essentially leading to a realistic number of state changes per satellite pass.