An Opportunity Spectrum Access for Multiuser with Randomized POMDP Framework

In this paper, an Opportunity Spectrum Access (OSA) strategy for multiuser was proposed. Assuming each CR user only can sense one channel at a time due to hardware restraints. And they only can sense one time during a slot time. The idle probability of each channel is predicted by the POMDP framework. If all CR users use the same OSA strategy with deterministic POMDP framework, collision will happen. Here, we present a new OSA strategy with randomized POMDP framework. It targets at maximizing the throughput of the entire cognitive radio network. The OSA also consider the service orders of the CR users and the CR user with high service order will have more chance to access the idle channels. We can see from the simulation results that the OSA with randomized POMDP framework can work for multiuser and work more efficiently than OSA with deterministic POMDP framework only for single user.