Tactical beamforming against high-power reactive jammer

Beamforming can spatially filter out a jamming signal and effectively obtain the desired directional gain. However, due to side-lobe, blunt beam of main-lobe, fault adaptation, and so forth, a targeted signal can be leaked to a reactive jammer. By sensing the leaked signal power, the reactive jammer concentrates its own power to the frequency band of the targeted signal. To solve this problem, we suggest parallel transmission of the target signal and a decoy signal in addition to conventional joint tx-rx beamforming for anti-jamming. Because the decoy signal uses different frequency band from the target, jammer cannot help distributing its jamming power between these signals. By measuring signal-to-jamming-plus-noise power ratio (SJNR) and channel capacity under the high-performance reactive jammer, we show that the proposed anti-jamming beamforming scheme outperforms the conventional one especially in the presence of high power jamming.