Aggregate Interference and Capacity-Outage Analysis in a Cognitive Radio Network

This paper presents a study on the interference caused by secondary users (SUs) due to misdetection and its effects on the capacity-outage performance of the primary user (PU) in a cognitive radio (CR) network assuming Rayleigh and Nakagami fading channels. The effect of beacon transmitter placement on aggregate interference distribution and capacity-outage performance is studied, considering two scenarios of beacon transmitter placement: a beacon transmitter located 1) at a PU transmitter or 2) at a PU receiver. Based on the developed statistical models for the interference distribution, closed-form expressions for the capacity-outage probability of the PU are derived to examine the effects of various system parameters on the performance of the PU in the presence of interference from SUs. It is shown that the beacon transmitter at the PU receiver imposes less interference and, hence, better capacity-outage probability to the PU than the beacon transmitter at the PU transmitter. Furthermore, the model is extended to investigate the cooperative sensing effect on aggregate interference statistical model and capacity-outage performance considering OR (i.e., logical OR operation) and maximum likelihood cooperative detection techniques. Simulation results are also provided to verify the developed analytical models.