Date Added: Feb 2011
Cognitive Radio (CR) techniques allow unlicensed Secondary Users (SUs) to opportunistically access underutilized primary channels that are licensed to Primary Users (PUs). The authors consider a multi-primary channel scenario in which the SUs cooperatively try to find these primary channel spectrum holes by limited spectrum sensing. The objective is to design the optimal sensing and accessing policy that maximizes the total secondary system throughput on the primary channels accrued over time, while satisfying a constraint on the probability of colliding with licensed transmissions. Although the problem can be formulated as a Partially Observable Markov Decision Process (POMDP), the optimal solutions are often intractable.