Differential Sensing for Rank-Limited Communications

This letter proposes a novel method called Differential Sensing to detect the number of passive targets, estimate the angle-of-arrival/departure and position of each target, and path-gain for each target reflection path in a bi-static joint communications and sensing system with rank-limited communication signals. The proposed method relies on beam sweeping operation consisting of beamforming and beam nulling at specific angles at the transmitter side and eigenspace analysis over the difference of the autocorrelation matrices of the corresponding observations at the receiver side. The detailed numerical results show the benefits of the proposed technique over commonly adopted baseline methods.