Three-Stage Super-Resolution Estimation of Target Parameter in OCDM ISAC Systems

Integrated sensing and communication (ISAC) systems employing orthogonal chirp division multiplexing (OCDM) signals offer enhanced spectral efficiency and interference resilience, yet face resolution limitations in parameter estimation constrained by time-frequency resources. This paper proposes a three-stage super-resolution framework to achieve high-precision target range and velocity estimation. First, coarse parameter estimation is performed via discrete Fourier transform-based processing on received echo signals. Second, signal compensation is implemented using coarse estimates and prior communication data. Finally, subspace projection combined with ambiguity resolution is employed to overcome physical resolution boundaries, enabling super-resolution parameter extraction. Simulation results demonstrate that the proposed approach can effectively enhance the system’s resolution, accurately estimate target parameters, and thereby improve the system’s sensing performance.