Performance Analysis of LEO-Terrestrial Systems in Presence of Doppler Effect

TL;DR

This paper introduces a stochastic geometry-based analytical framework to evaluate how residual Doppler shifts affect OFDMA systems in LEO satellite-terrestrial networks, highlighting the importance of considering Doppler effects in network design.

Contribution

It presents a novel analytical approach to model residual Doppler impact on OFDMA systems in LEO networks, incorporating spatial distribution and validating with simulations.

Findings

Residual Doppler significantly impacts coverage probability.

The analytical model accurately predicts Doppler effects.

Doppler compensation may not fully mitigate residual shifts.

Abstract

In this paper, we present a novel stochastic geometry-based approach to analyze the effect of residual Doppler shift on orthogonal frequency-division multiple access (OFDMA) systems in low earth orbit (LEO) satellite-terrestrial networks. Focusing on multiuser systems employing common Doppler compensation, we analytically formulate the coverage probability by explicitly capturing the loss of OFDMA subcarrier orthogonality caused by geometry-induced residual Doppler through inter-carrier interference. The analysis accounts for the spatial distribution of ground terminals within the serving satellite's cell and is validated through extensive Monte-Carlo simulations for both S-band and Ka-band settings. The results demonstrate the high accuracy of both the Doppler shift approximation and the derived coverage probability expression, while also highlighting the significant impact of residual Doppler shift, even after compensation, emphasizing the necessity of considering this effect in the design of future satellite networks.