QR versus IQR algorithms for adaptive signal processing: performance evaluation for radar applications

The authors present a novel systolic array for minimum variance distortionless response (MVDR) adaptive beamforming, based on inverse QR (IQR) updates. The array is made up of O(N²+mN) processing cells, N being the number of degrees of freedom and m the number of look directions, and allows a fully parallel and pipelined weight extraction. In this respect the proposed array overcomes the limitations of existing systolic adaptive beamformers which require O(mN²) cells and/or do not allow parallel pipelined weight extraction. In addition, the paper considers CORDIC realisation of systolic adaptive beamformers. Finally, it provides a comparative study, via simulation experiments, on the numerical properties of various systolic adaptive beamformers when implemented with CORDIC cells and operating on typical radar data