Reduced-rank STAP for airborne radar based on switched joint interpolation, decimation and filtering algorithm

We present an adaptive reduced-rank signal processing technique for airborne phased array radar applications. The proposed method performs dimensionality reduction by using a reduced-rank switched joint interpolation, decimation and filtering algorithm (RR-SJIDF). A multiple-processing-branch (MPB) framework, which contains a set of jointly optimized interpolation, decimation and filtering units, is employed to process the observations. The output is switched to the branch with the best performance among the available ones. In order to design the decimation unit, we present the optimal decimation scheme and also a low-complexity decimation algorithm. We then develop a low-complexity recursive least squares (RLS) algorithm for the proposed scheme. Simulations results show that the proposed RR-SJIDF STAP algorithm converges at a very fast speed and provides a considerable signal-to-interference-plus- noise-ratio (SINR) performance improvement over the state-of- the-art reduced-rank schemes.