MIMO Radar Joint Heart Rate and Respiratory Rate Estimation and Performance Bound Analysis

This letter investigates the non-contact heart rate (HR) and respiratory rate (RR) joint estimation employing multiple-input multiple-output (MIMO) radar with widely separated antennas. By developing a signal model for the HR and RR estimation using the MIMO radar, where the initial phases for HR and RR, as well as the reflection coefficients, are deterministic but unknown, we propose an HR-RR joint estimator. Unlike the existing methods, the theoretical performance of the HR and RR estimation is analyzed for the first time, where the corresponding Cramer-Rao Bounds (CRBs) are derived. These bounds provide the first theoretical performance benchmark for this type of radar-based estimation and guide the system parameters design to enhance the HR and RR estimation performance, thereby avoiding the complex numerical computations involved in the joint estimator. It is shown that the proposed method outperforms traditional methods and the CRB can provide the guidance for system parameter optimization.