A Novel CC Selection Scheme for Spectrum Aggregation in Cognitive Radio

In spectrum aggregation (SA), two or more component carriers (CCs) of different bandwidths in different bands can be aggregated to support wider transmission bandwidth. CC selection is the new radio resource management (RRM) functionality introduced in LTE-Advanced. The current CC selection schemes do not consider the cognitive radio (CR) condition and are not suitable for CC selection in CR. Consequently, the authors propose a novel CC selection scheme in CR, termed as cognitive radio based least load (CR-LL) scheme. Under a dynamic traffic model, an equivalent throughput of the CCs based on the knowledge of primary users (PUs) is given. On this basis, the CR users data transmission time of each CC is equal in CR-LL. The simulation results show that CR-LL has the better performance than the current CC selection schemes in the CR condition. Meanwhile, CR-LL has the same performance as the current CC selection schemes when there are no PUs in the CCs.