Spoofing optimization over Nakagami-m fading channels of a cognitive radio adversary

We examine the performance of a cognitive radio system in a hostile environment where an intelligent adversary tries to disrupt communications by spoofing. We analyze a cluster-based network of secondary users (SUs), where sensing is performed by the cluster head. The adversary may attack during the sensing interval to limit access for SUs by transmitting a Gaussian noise spoofing signal. We present how the adversary can optimally allocate power across subcarriers during the sensing interval over Nakagami-m fading channels, using an optimization approach specific to this problem. We determine a worst-case optimal spoofing power allocation, when the adversary has knowledge of the system, which gives a lower bound to the average number of accessible bands for SUs under attack.