Aspect of security in the cognitive relay assisted interference channels

We consider the problem of secret communication through cognitive relay assisted interference channels where the secondary users are allowed to transmit simultaneously with the primary users over the same channel in the presence of an eavesdropper. At first, we investigate the effect of diversity in enhancing security of the cognitive interference channels with multiple relays. Then, the performance of cognitive relay beamforming system is optimized in such a way that the eavesdropper gets zero bits of information maintaining interferences at the primary receiver under a certain threshold. Finally, we characterize secrecy rate at the primary and secondary receivers compensating interferences using zero-forcing (ZF) precoding at the cognitive relay.