Resource allocation for maximizing secrecy rate in presence of active eavesdropper

In this paper, we consider the problem of power allocation of OFDM user in the presence of an active attacker. The malicious user has the ability of either eavesdropping of ongoing connection or jamming it. However, it can not function as both the eavesdropper and jammer at the same time. The attacker´s policy is to choose between eavesdropping and jamming such that the ultimate secrecy rate is minimized. Hence, the legitimate user considers the worst case at which the ultimate secrecy rate is assumed to be the minimum between the achievable rate of each case. Under the total transmit power constraint, the user distribute the transmit power over subcarrier such that the total secrecy rate is maximized. By simulation, we evaluate the efficiency of the proposed scheme.