To improve the channel utilization and throughput performance of CRN, this paper proposed a new adaptive spectrum handoff strategy, which emphasized the priority of primary user, considered the influence of the arrival rate of the primary user(PU) on the communication of the secondary user(SU) and limited the interference power of the secondary user to the primary user, and SUs adapted to a reactive or a proactive handoff strategy accordingly. This adaptive handoff strategy established the Markov chains between primary and secondary users, and gave the steady-state probabilities respectively. From the steady-state probability and throughput under different states, it derived the analytic expressions of system throughput and channel utilization. And it established a Markov chain for the transmission between secondary users, derived the time to transfer control information between secondary users. Numerical results show that the proposed adaptive handoff strategy has higher throughput and channel utilization than the CSMA-based random access approaches, and can be used to derive the time to transfer control information between secondary users.

[2021-03-05] Printed Article /doc/2020.02.0062/v2