Optimal Power Control for Real-time Applications in Cognitive Satellite Terrestrial Networks

Cognitive satellite terrestrial networks have received considerable attention as a promising candidate to address the spectrum scarcity problem in future wireless communications. When satellite networks act as cognitive users in the networks, power control is a significant research challenge in the uplink case, especially for real-time applications. We propose two optimal power control schemes for maximizing the delay-limited capacity and outage capacity, respectively, which are useful performance indicators for real-time applications. From the long-term and short-term aspects, average and peak power constraints are adopted, respectively, at the satellite user to limit the harmful interference caused to the terrestrial base station. Extensive numerical results demonstrate the impact of interference constraints and channel condition parameters on the performance limits of satellite users.