Spatially Diverse Dual-Function Radar-Communications with Reduced Self-Interference

The element-level control afforded by a digital array provides the necessary flexibility to realize spatially diverse transmissions that can perform multiple simultaneous functions in different spatial directions. Here, a co-designed transmission that simultaneously produces a high-power radar beam and a lower power communications beam is considered. Previous waveform design methods of producing this type of transmission produce narrow spatial nulls for the opposing function in the desired transmission directions. For these designs, there is potential for self-interference between the beams if there are errors in communications pointing direction or backscatter over an angular swath in the radar main beam. In this paper, this waveform design method is reformulated to reduce potential self-interference by widening spatial nulls of interfering energy during the optimization process. An example transmission scenario is provided to illustrate the concept.