FMCW Waveform Design With Good Correlation Level for the Joint Radar and Communications

In this paper, we propose frequency modulated continuous wave (FMCW) design and receive processing techniques for joint radar and communications. Our approach simultaneously takes into account the correlation property of waveform and interference mitigation for radar while enabling information embedding (IE) for communications. Specifically, we adopt an advanced IE strategy using hybrid modulations to enhance communication rates. Meanwhile, we seek to minimize the integrated sidelobe level of FMCW waveform to optimize the correlation level and leverage waveform agility to mitigate interference for radar. The design leads to a non-convex optimization problem. To address it, we choose to directly manipulate the polynomial coefficients in the phase elements of FMCW waveform and reformulate it into a proper form. We then make use of the majorization-minimization technique to find solutions through iterations for solving the reformulated design. A closed-form solution is obtained at each iteration. Our major contribution also lies in proposing a demodulation method for communications. Simulation results verify the effectiveness of the proposed FMCW design and its superiority over existing work.