Full-duplex capable multifunction joint radar–communication–security transceiver with pseudonoise–orthogonal frequency-division multiplexing mixture waveform

The authors investigate the performance of an original multifunction system with two in-band full-duplex capable joint radar, communications and security (JRCS) transceivers in the presence of an eavesdropper. The system concept can be generalised to a network of more than two JRCS transceivers and multiple eavesdroppers, despite the present study focusing on the three-node scenario. By combining a bandlimited pseudonoise waveform with a data-containing orthogonal frequency-division multiplexing (OFDM) waveform, the authors are able to ensure a certain jamming-to-signal power ratio (JSR) at the eavesdropper, whilst ideal synchronisation ensures that jamming causes no deterioration to their own data transfer or radar sensing performance as it is possible to remove just the known pseudonoise waveform. To validate the system, the authors investigate through simulations the OFDM symbol error rates of all the receivers, radar target signal-to-interference-plus-noise power ratios as well as receiver operating characteristic curves, and eavesdropper's detection signal-to-noise power ratios through two-branch receiver cross-correlation. The results show that already a very low JSR of −20 dB can improve physical-layer security without a significant increase in friendly symbol error rate or deterioration in radar performance. Additionally, other full-duplex transceivers potentially occupying the same radio resources improve the secrecy even further.