Power allocation and relay selection for cognitive networks with Poisson distributed primary users

In this work, we consider a cooperative cognitive radio network with Poisson distributed primary users. We first provide an optimal power allocation for the secondary user while guaranteeing quality of service of the primary users and analyze the outage probability of the secondary user when the optimal power is given. To minimize the outage probability of the secondary user, relay selection is considered among candidate relays. Since an optimal relay selection scheme needs high processing complexity, we propose a simple suboptimal relay selection strategy with low complexity. Numerical results show that the proposed strategy performs almost the same as the optimal relay selection scheme.