Max-Max User-Relay Selection Scheme in Multiuser and Multirelay Hybrid Satellite-Terrestrial Relay Systems

We consider a hybrid satellite-terrestrial relay system that employs a multiantenna satellite to communicate with multiple users via multiple amplify-and-forward relays. We employ a max-max user-relay selection scheme to minimize the outage probability of the system. Considering both variable and fixed gain relaying protocols, we derive exact closed-form expressions of outage probability and their asymptotic behavior over independent and identically distributed fading channels for each hop. Numerical and simulation results validate our analysis and highlight the performance gains of the proposed scheme.