Radio resource allocation for OFDMA-based cognitive systems

This paper addresses the problem of wireless resource allocation in OFDMA-based cognitive radio cooperative systems. The objective is maximizing the total throughput and minimizing the transmission power of cognitive transmissions while guaranteeing fairness between the different cognitive users queues. The proposed radio resource allocation algorithm is based on maximizing the rate to power ratio. We also investigate the conflict resolution problem by suggesting a Conflict Resolution rate-based procedure to allocate conflicted subcarriers. Moreover, to secure cognitive transmissions we propose a double reservation procedure based on rate to power ratio margin RPRM, and thus to allocate secondary subcarriers. We propose to serve urgent transmissions, based on a fairness indicator. Simulations show the performance and the efficiency of the proposed algorithm.