Spectrum sensing time and cognitive outage performance tradeoff in cognitive radio networks with interference power constrains

In this paper, we proposed a cooperative cognitive transmission scheme and design the optimal spectrum sensing overhead with power allocation to maximum the overall cognitive outage performance which jointly considering the spectrum sensing phase and data transmission phase in cognitive radio networks. Specifically, in the first phase, cognitive resource senses the licensed channel and determines the state of primary user. In the second phase, cognitive resource transmits its data to destination via cognitive relay according to different spectrum sensing results with interference power constraint (protect the primary user from harmful interference). We drive a closed-form expression of outage probability for the proposed scheme over Rayleigh fading channels. Numerical results show that, there is a tradeoff in determining the spectrum sensing overhead in order to maximize the cognitive outage performance with the protection of primary user.