Jammer avoidance for dual-function radar-communications using FSK and independent null steering

Abstract

In this paper, we propose a novel method for dual-function radar-communication(DFRC) system. Our focus is on radar being used for communications in parallel to conventional target tracking and/or surveillance assignment. In the proposed setup, the main beam is directed toward the targets as primary radar function, whereas, communication is performed through the sidelobes as secondary function. In addition, the nulls are used to avoid the jammers. A sophisticated null steering feature has been incorporated to deal with the moving jammers. In this null shifting, only the proposed null will be shifted, whereas, rest of the antenna radiation pattern including main beam and the other sidelobes will remain undisturbed. We also propose a new information embedding to transmit the communication signal in the radar emission by using the frequency shift keying (FSK) as orthogonal waveforms to transmit binary information towards the communication receivers and analyzing the impact of the FSK signals on the radar range measurements. Simulations are carried out and the results indicate the validity and performance of the proposed idea in terms of interference mitigation as well as Bit Error Rate (BER).