Joint Range-Velocity-Azimuth Estimation for OFDM-Based Integrated Sensing and Communication

Orthogonal frequency division multiplexing (OFDM)-based integrated sensing and communication (ISAC) is promising for future sixth-generation mobile communication systems. For OFDM-based ISAC systems, it is important to accurately sense the target’s parameters. This paper studies the three-dimensional joint estimation (3DJE) of range, velocity, and azimuth for OFDM-based ISAC systems with multiple receive antennas. First, we establish the signal model and derive the Cramér-Rao bounds (CRBs) on the 3DJE. CRBs are widely used benchmarks that provide the theoretical lower bounds of the variances for unbiased estimation. Furthermore, an auto-paired super-resolution 3DJE algorithm is proposed by exploiting the reconstructed observation sub-signal’s translational invariance property in the delay, Doppler, and angle domains. Finally, with the 5G New Radio parameter setup, simulation results show that the proposed algorithm achieves better estimation performance and its root mean square error is closer to the square root of CRBs than existing methods.