Distributed Cooperation in Cognitive Radio Networks: Overlay Versus Underlay Paradigm

This paper studies the benefits that cooperation brings to a cognitive radio network. The proposal in this paper considers that secondary unlicensed users are allowed to opportunistically use the radio spectrum allocated to the primary licensed users, as long as they agree on facilitating the primary user communications by cooperating with them. We refer to this approach as overlay paradigm for cognitive radio and we compare this to the underlay paradigm, according to which cooperation techniques among primary and secondary users are not exploited. To model these schemes we make use of theory of exact potential games. We analyze the convergence properties of the proposed games and we evaluate the outputs in terms of quality of service perceived by both primary and secondary users, outage probability and interference temperature, showing that the overlay paradigm for cognitive radio is a promising framework.