Secrecy Rate Maximization for MIMO DFRC System With Statistical CSI

This letter addresses a security concern of the multiple-input multiple-output (MIMO) dual-functional radar-communication (DFRC) system where the target is regarded as a potential eavesdropper. A non-convex optimization problem of ergodic secrecy rate maximization is formulated under the transmit power constraint and the transmit waveform similarity constraint. By using the large-system analysis results and Taylor series approximation, we derive a closed-form optimal transmit covariance matrix, which only depends on statistical channel state information (CSI) and facilitates the trade-off between ergodic secrecy rate and radar beampattern. Numerical simulations demonstrate the effectiveness of the proposed method.