MIMO versus conventional radar performance against jammers

It has been claimed that MIMO radars perform better than conventional radars against repeater and hot clutter jammers (jammer signals reflected from the ground into the radar). It is shown here that conventional radars can perform as well if not better than MIMO radars against these jammers as well as against barrage noise jammers. The results are presented in tutorial form without heavy math. Instead physical explanations are given for these results. Applied here to reject the barrage jammer and hot clutter is the Adaptive-Adaptive Array Processing (AAAP) technique which makes use of the information available as to where the jammers are rather than assuming there location is not known as done for the classical sample matrix inversion (SMI) method. This is reminiscent of the KA-STAP technique used by DARPA. It also could be called Cognitive Adaptive Array Processing (CAAP). The method reduces the transient time (the number of time samples needed to calculate the interference covariance matrix) by orders of magnitude. Also the interference covariance matrix size is reduced by orders of magnitude and in turn the computation of its matrix inverse. Finally this method reduces the sidelobe degradation usually resulting from using the SMI method. The AAAP technique lends itself well to both the MIMO and conventional array systems when digital beam forming is used.