Mechanism of spectrum sharing with QoS support for secondary users in cognitive radio networks

We originally design a mechanism of spectrum sharing for cognitive radio networks (CRNs), which can protect secondary users from dropping call and improve the user capacity compared with traditional scheme. Continuous time Markov process is adopted for modeling interactions between primary users and secondary users in proposed mechanism. Based on quasi-birth and death process (QBD) theory, we present the solutions to stead-state probability for our model. Simulation results verify the validity of theoretical analysis. The performance improvement for cognitive system and the effect on primary system are addressed by comparing with traditional scheme.