Power-controlled cross-layer scheduling

Power-Controlled Cross-Layer Scheduling is proposed for real-time multimedia-applications in cellular wireless networks. The new scheme borrows elements from Proportional Fair Scheduling, from which it differs in that it can satisfy hard delay constraints, and improves on exploiting multiuser diversity gains by selectively excluding users from scheduling decisions based on their rate demands. The performance of the new scheduler is compared to performance bounds from multiuser information theory. Then, the basic concept is extended to a real-world scenario, in which the long-term path losses of all users will change over time: this necessitates the introduction of a power control scheme, that, if carefully designed, “inverts” the long-term pathloss of the channel, but not the fast fading. An analysis of the outage probability characteristic shows near-optimum behavior for delay-constrained applications and reveals huge performance gains for demanding users, compared to classical proportional fair scheduling.