Outage probability of cognitive relay network with transmit power and interference constraints

This paper investigates the outage probability of the cognitive relay network with cooperation between the secondary source (SS) and the secondary relays (SR) which use a decode-and-forward (DF) scheme. To guarantee the quality of service (QoS) of the primary user (PU), the interference from the secondary network (SN) has to be lower than what the PU can tolerate. In other words, there is a constraint on the transmit power of the SN. A relay selection criterion is adopted to choose the “best” relay which retransmits the signal from the transmitter to the destination in the SN. Additionally, interference from the primary network (PN) to the SN is also considered, and its effect on the performance of the SN in terms of outage probability is focused on. Simulation results are provided to show the outage probability of the SN and the effect of the PN on the performance of the SN.