Adaptive MIMO radar waveforms

Multiple-Input, Multiple-Output (MIMO) radars enhance performance by transmitting and receiving coded waveforms from multiple locations. To date, the theoretical literature on MIMO radar has focused largely on the use of ldquoorthogonal waveforms.rdquo Practical approaches to approximate orthogonality (e.g., via waveforms characterized by low cross-correlation and low autocorrelation sidelobe levels) have also started to emerge. We show, however, that such waveforms can still perform poorly in adaptive systems. For adaptive MIMO radar systems, another factor is equally important; we call it ldquoMIMO Cancellation Ratio (CR).rdquo In this paper, we introduce MIMO CR and assess the performance of standard waveform classes (e.g., CDMA, TDMA and FDMA) with regard to this new metric. Then, we describe how to create new waveforms that facilitate higher performance adaptive cancellation. Finally, we apply our waveform design methodology to the problem of airborne MTI radar, in which STAP techniques are used to mitigate clutter.