  With the advent of intelligent jammers, jamming attacks have become a more
severe threat to the performance of wireless systems. An intelligent jammer is
able to change its policy to minimize the probability of being traced by
legitimate nodes. Thus, an anti-jamming mechanism capable of constantly
adjusting to the jamming policy is required to combat such a jammer.
Remarkably, existing anti-jamming methods are not applicable here because they
mainly focus on mitigating jamming attacks with an invariant jamming policy,
and they rarely consider an intelligent jammer as an adversary. Therefore, in
this paper, to employ a jamming type recognition technique working alongside an
anti-jamming technique is proposed. The proposed recognition method employs a
recurrent neural network that takes the jammer's occupied channels as inputs
and outputs the jammer type. Under this scheme, the real-time jammer policy is
first identified, and, then, the most appropriate countermeasure is chosen.
Consequently, any changes to the jammer policy can be instantly detected with
the proposed recognition technique allowing for a rapid switch to a new
anti-jamming method fitted to the new jamming policy. To evaluate the
performance of the proposed recognition method, the accuracy of the detection
is derived as a function of the jammer policy switching time. Simulation
results show the detection accuracy for all the considered users numbers is
greater than 70% when the jammer switches its policy every 5 time slots and the
accuracy raises to 90% when the jammer policy switching time is 45.
