  This paper considers mutual interference mitigation among automotive radars
using frequency-modulated continuous wave (FMCW) signal and multiple-input
multiple-output (MIMO) virtual arrays. For the first time, we derive a general
interference signal model that fully accounts for not only the time-frequency
incoherence, e.g., different FMCW configuration parameters and time offsets,
but also the slow-time code MIMO incoherence and array configuration
differences between the victim and interfering radars. Along with a standard
MIMO-FMCW object signal model, we turn the interference mitigation into a
spatial-domain object detection under incoherent MIMO-FMCW interference
described by the explicit interference signal model, and propose a constant
false alarm rate (CFAR) detector. More specifically, the proposed detector
exploits the structural property of the derived interference model at both
\emph{transmit} and \emph{receive} steering vector space. We also derive
analytical closed-form expressions for probabilities of detection and false
alarm. Performance evaluation using both synthetic-level and phased array
system-level simulation confirms the effectiveness of our proposed detector
over selected baseline methods.
