Outage and ergodic capacity analysis for cognitive radio network under the impact of aggregate interference over Nakagami-m fading

In a cognitive radio network (CRN), the performance of secondary users depends on the cochannel interference generated by the primary and the secondary transmitters. Therefore, the characterization of aggregate interference (AI) in such type of networks is of prime importance. The characterization of AI at the primary receiver due to multiple cognitive users has been reported in the literature, but the impact of this AI on the performance of secondary receivers has not been investigated. In this paper, the closed form expressions have been derived for the outage probability based on the complementary cumulative distribution function (CCDF) of the received signal to interference ratio (SIR) at secondary receiver. This analysis is carried out under the impact of AI generated by multiple secondary networks under Nakagami-m fading channel. The system model is designed based on stochastic geometry tools where the interfering nodes are assumed to be distributed as a homogeneous spatial Poisson point process (PPP). Further, the closed form expressions have been derived for the ergodic capacity of secondary networks for different parameters of the Nakagami-m fading channel. The results show that the outage probability and ergodic capacity depend upon not only the threshold level of the primary receivers but also a function of received SIR at the secondary receiver, network topology, and the parameters of Nakagami-m fading channels.