Decoy Signal Based Strategic Beamforming Against High-Power Reactive Jamming

Array beamforming (BF) has received considerable attention as a means of anti-jamming by combining desired signals constructively and jamming signals destructively. However, even with BF, the state-of-the-art reactive jammer (RJ) can easily detect the target channels from the leakage of the transmit power and concentrate its own power to the detected band to degrade communication performance. In this paper, we attempt to mitigate this problem by exploiting fake information, the so-called decoy signal, and proper BF at the transmitter and the receiver, and show that it is possible to deceive the RJ into allocating a large portion of its own power to the decoy signal. In this regard, we attempt to maximize the signal-to-jamming-plus-noise power ratio (SJNR) at the receiver and the signal-to-leakage power ratio at the transmitter by optimizing the BF strategy. Through numerical simulations measuring the SJNR and the channel capacity, we demonstrate the effectiveness of the proposed BF scheme, especially in high-power RJ environments.