Spatially-modulated radar waveforms inspired by fixational eye movement

We consider a class of MIMO radar emissions in which a coherent spatial beam is formed while the direction is modulated during the pulse width. This type of spatial modulation has a direct analog to the rapid, small movements of the human eye during fixation (staring) to enhance contrast and sensitivity to fine detail. To replicate this passive sensing capability of the eye for the active sensing modality of radar we leverage and expand the continuous phase modulation (CPM) framework for code-to-waveform implementation and thereby realize a physical delay-angle coupled emission. Through analysis of a defined angle-delay ambiguity function for specific waveform/spatial modulation examples it is shown that enhanced discrimination is enabled at the cost of some SNR loss, which may be an acceptable tradeoff for some applications.