Low-complexity Channel Reservation Design Scheme in Cognitive Radio Networks

In this paper, a low-cost channel reservation design scheme is proposed for cognitive radio networks (CRNs) to achieve call level quality of service (QoS) provisioning. An optimization problem is formed to minimize the handoff call dropping probability with a hard constraint on the new call blocking probability, and then is rewritten to another problem where only the new call blocking probability is involved. An analytical expression of the new call blocking probability is derived through modeling the channel occupancy situation of the system (including primary user network and CRN) through a one-dimension continuous time Markov chain instead of the commonly used two-dimension one. Then, the optimal number of reserved channels is determined by solving the aforementioned rewritten problem. The computational complexity of the proposed method is very low which enables its applications in high dynamic scenarios like CRNs. Simulation results verify the accuracy of the analytical expression and the effectiveness of the optimization.