Using Widely Separated MIMO Antennas for UAV Radar Direction-of-Arrival Estimation

Distributed sensor systems can reduce inter-system interference on platforms like unmanned aerial vehicles (UAVs) when different radio frequency (RF) systems are operated in parallel in a confined space. Further densification of airspace and an increasing degree of automation lead to additional requirements for the safety, reliability and accuracy of these types of sensor systems. This paper investigates the possibilities of using digital beamforming (DBF) and compressive sensing (CS) with widely distributed antenna arrays as an alternative to conventional multiple-input multiple-output (MIMO) arrays colocated in a central position. It can be shown that, taking into account path length differences caused by large antenna spacings, accurate direction-of-arrival (DoA) estimation is still possible, with the benefit of allowing a more relaxed antenna placement with regard to inter-system interference.