Optimal jamming strategies in digital communications — Impact of modulation

Jamming attacks can significantly impact the performance of wireless communication systems, and can lead to significant overhead in terms of re-transmissions and increased power consumption. This paper considers the problem of optimal jamming over an additive white Gaussian noise channel. We derive the optimal jamming signal for various digital amplitude-phase modulated constellations. We show that it is not always optimal to match the jammer´s signal to the victim signal in order to maximize the error probability at the victim receiver. Connections between the optimum jammer obtained in this analysis and the well-known pulsed jammer, popularly analyzed in the context of spread spectrum communication systems are illustrated. Further, we evaluate the value of the knowledge of the victim´s modulation schemes by comparing the performance of the optimal jamming signals with conventional additive white Gaussian noise jamming. Numerical results are presented in order to validate the theoretical inferences presented.