Spectrum occupancy analysis of cooperative relaying technique for cognitive radio networks

Dynamic Spectrum Access (DSA) is a successful solution for the spectrum scarcity problem. In DSA, unlicensed users can gain access to licensed spectrum in a way that does not harm the licensed transmission. Many technical solutions are proposed to efficiently facilitate DSA. This paper analyzes the benefits of using cooperative relaying technique on the spectrum occupancy for the unlicensed transmissions. A slotted access with interweave spectrum sharing is modeled using stationary discrete time Markov chains for both non-cooperative and cooperative unlicensed transmissions. Furthermore, the effect of the cooperation level among the unlicensed users on the achieved throughput is investigated. The results show that the mechanism of cooperative relaying is more efficient in utilizing the unused spectrum especially in crowded spectrum. Moreover, the relative average throughput increases as the cooperation increases due to efficient utilization of the spectrum holes.