Doppler-offset waveforms for MIMO radar

Abstract

In a Multiple-Input, Multiple-Output (MIMO) radar, independent waveforms are transmitted from different locations, with the resulting reflections processed to form a "virtual antenna array" that is larger than the physical aperture of the radar. This paper examines the design of Doppler-offset waveforms for use in adaptive MIMO GMTI radar systems. Such waveforms provide good adaptive cancellation performance, but are also subject to strong range and Doppler ambiguities. We analyze these ambiguities, and show how they relate to array topology and waveform design. Then, we describe a new waveform approach, called "Dithered DDMA," which enables high performance clutter cancellation over large range-Doppler regions without introducing ambiguous ranges or blind speeds, and without increasing the computational load on the MIMO processor.