A Robust Joint Sensing and Communications Waveform against Eavesdropping and Spoofing

In this paper we propose a joint Radar and Communications waveform for next-generation wireless networks (e.g., 6G, next-generation Wi-Fi). The proposed waveform is a multiple carrier signal with each carrier a chirp-like wave instead of a sinusoid in OFDM. The signal is a parameterized waveforms with two adjustable parameters, and could be generated by affine Fourier transform once the parameters are given. We analyze the communications and ranging performances of the waveform by deriving the transmitting-receiving model and the ambiguity function and compare them with an OFDM signal. Further, we investigate the secrecy of the waveform in both communications and ranging and show the sensitivity of the waveform to the mismatch of these parameters. When these parameters are kept secret from the potential adversary, the legitimate signal cannot be demodulated correctly by the eavesdropper and the waveform spoofing attack is also invalided. Simulations demonstrate that the proposed multiple-carrier chirp waveform has better performance than OFDM signal in both communications and ranging, which has lower BER in fading channel and higher resolution in ranging. We also evaluate the performance under eavesdropping and spoofing attack(1).