Opportunistic Channel Sharing Based on Primary User Transition Probabilities in Dual Mode Cognitive Radio Networks
In cognitive radio networks, it is important to effectively use the under-utilized spectrum resources without affecting the primary users. In an underlay system, cognitive users are allowed to share the channel simultaneously with primary users with the restriction on interference level but not in an overlay system. In this paper, the authors consider a system where cognitive users can switch between overlay and underlay modes of operation in order to improve their throughput. The results, based on Markov chain analysis, are satisfactorily verified using MonteCarlo simulation. It is shown that proper selection of transmission mode can provide greater improvement in throughput for cognitive users.