Collision-driven random multiuser opportunistic spectrum access

In this paper, the problem of distributed multiuser Opportunistic Spectrum Access is studied based on Partially Observable Markov Decision Process (POMDP), where the channels are partially observed by secondary users (SUs) constrained by hardware and energy. Considering the similarity of spectrum environment, the decision of every secondary user may be the same, which leads to collisions. Comparing with the previous works, we propose a “collision-driven random” strategy, where the activities of secondary users are relatively steady but changing over time. If a secondary collides with others when transmitting data in one time slot, it may take the action of selecting a channel randomly according to choosing probability at next time slot. Otherwise, the secondary user stays on the current channel. Observing the simulation results, the upgrade of performance is up to 100% compared with the existing strategies.