Reducing On-Board Interference and Angular Ambiguity Using Distributed MIMO Radars in Medium-Sized Autonomous Air Vehicle

Current research focuses on radio frequency (RF) systems for autonomous driving and urban air mobility, sharing demands for utmost reliable communication and radar systems installed in confined spaces. As a result, coexistence considerations are becoming increasingly important. By dividing antenna groups into subgroups and increasing their spacing, mutual interference can be reduced. In our research, we seek to reduce RF interference effects in medium-size autonomous aerial vehicles. To this end, distributed MIMO radar arrays are employed to reduce out-of-band interference effects between the radar and other on-board RF systems, while at the same time offering angular diversity for better detectability of fluctuating targets. To solve the issue of angular ambiguity associated with distributed arrays, we combine our setup with compressed sensing-based DoA estimation, while optimizing the sensing matrix such that it matches the resulting grating lobe structure. Our results show that the proposed bistatic MIMO setup is able to outperform monostatic setups for targets with angle-dependent radar cross sections. The first part of the article reviews relevant radar signal and array processing techniques in a survey style. Based on this, it then provides an analytical framework to explain how these techniques are combined to attain our goals.