Maximizing Mutual Information for Covert Sensing in Joint Radar-Communication Systems

While traditionally radar and communication systems have operated independently, in-depth research has revealed that combining them can lead to significant advantages. This combined approach offers an improvement in overall system functionality by simplifying structures, reducing hardware usage, enhancing efficiency, mitigating electromagnetic interference, etc. In this paper, we formulate an optimization scheme for a joint radar and communication (JRC) system that allows the Radar to simultaneously estimate channel parameters from the target returns and decode the received communications signals. The primary objective is to maximize the mutual information (MI) exchange by optimizing the Radar’s transmit power while guaranteeing a predefined threshold data rate for data transmission and the desired threshold for covertness requirement. Numerical results show that the Radar can effectively adjust its transmit power to successfully hide its presence from the target up to over ninety percent and also meet the minimum requirement of information rate.