Outage Analysis of Cognitive Relay Networks with Relay Selection under Imperfect CSI Environment

In this letter, we study the outage performance of cognitive relay networks with multiple primary users in imperfect channel state information environment. Specifically, an exact closed-form outage expression is derived, which provides an efficient means to evaluate the effect of system parameters. In order to gain more insights, simple expressions for the outage probability is obtained at asymptotic high SIR regime, which is only determined by the second hop of the considered system. Monte Carlo simulations are also provided, which corroborate the correctness of the analytical results. The finding suggests that the primary network only affects the coding gain of the considered system.