Overview of Spectrum Sharing and Dynamic Spectrum Allocation schemes in Cognitive Radio Networks

Cognitive radio is a relatively new technology that improves spectrum utilization. The efficient assignment of unlicensed users to unused spectrum is a major issue. Spectrum allocation is a critical technique for limiting and avoiding interference between cognitive radio devices and licensed primary users, allowing for more efficient wireless radio spectrum use. Various state of art methods and challenges during spectrum sharing and allocation approaches in cognitive radio networks in light of anticipated improvements with respect to next-generation wireless communication applications are discussed in this paper.