Performance Analysis of Multitier Terrestrial-LEO-GEO Communication Systems

In this article, we investigate the outage probability (OP) of a multitier dual-hop terrestrial-low Earth orbit (LEO) satellite-geostationary Earth orbit (GEO) satellite hybrid wireless communication system. The system comprises multitier LEOs and one GEO act as relays in the uplink, which help the terrestrial ground station (GS) (S ) transmit information to the terrestrial destination (D ). In uplink transmission, we introduce a 1-D hardcore point process (1-D HCPP) to model different altitudes of LEOs' different tiers. We also use a generalized selection combining (GSC) technique to achieve a tradeoff between maximum ratio combining (MRC) and selection combining. In downlink, GEO offers the maximum coverage to randomly distributed D. Moreover, the independent identically distributed (i.i.d.) Nakagami-m fading and shadowed Rician distribution are brought to model the different channels. Finally, Monte Carlo simulations are presented to affirm the precision and accuracy of the derived analytical models and the proposed analysis. This framework offers crucial insights for system designers and network operators, enabling the optimization of resource allocation, relay strategies, and overall reliability in terrestrial-satellite hybrid networks.