Efficient distributed scheduling in cognitive radio networks in the many-channel regime

The design of efficient and distributed scheduling algorithms is essential to garner the full potential of cognitive radio networks. In this paper, we propose a distributed OFDM-based scheduling algorithm, named collision-queue-regulated algorithm, which aims to limit the collision rate to a level imposed by primary users of a cognitive radio network. Via a novel equivalent-queue-system analysis, we prove that the proposed algorithm can achieve at least a constant fraction of the asymptotic capacity region in the many-channel regime. Our numerical studies indicate that the proposed distributed collision-queue-regulated algorithm achieves a throughput very close to that achievable by a centralized throughput-optimal back-pressure-based scheduling algorithm.