Worst-Case Jamming Attack and Optimum Defense Strategy in Cooperative Relay Networks

In this letter, we consider multiple peer to peer communications using a trusted relay network encountered to the jamming network attack. The jammers, that are equipped with beamformer are trying to minimize the maximum signal-to-interference-plus-noise ratio (SINR) at the destinations subject to the constraint that the maximum SINR at each of the relay nodes does not exceed a predefined threshold level. This optimization problem would cause the maximum destruction in the legitimate nodes. To address this optimization problem, we propose a closed-form solution. On the other hand, the relays are trying to avert the jamming attack by adjusting the beamformer weights in such a way that maximum SINR at destination nodes occurred while keeping the total transmission power of the relays under a specified threshold. For solving the second optimization problem, we propose a closed-form solution, as well. It has been shown that the proposed closed-form method has extremely lower complexity compared to the bisection algorithm, while their performances are almost identical.