Algorithmic, architectural, and beam pattern issues of sidelobe cancellation

Various important issues concerning the sidelobe cancellation (SLC) approach for suppressing sidelobe interference signals in radar are investigated. The concepts are presented in a tutorial manner and include: formulating the calculation of the complex weights for the auxiliary channels as an exact least-squares (LS) problem; computing the LS weights using orthogonal transformation for improved numerical accuracy; and mapping orthogonalization-based algorithms onto systolic arrays. The problem of excessive degrees of freedom (EDOF) associated with utilizing too many auxiliary elements when a relatively small number of jammers are present, is also considered. A divisionless orthogonalization-based algorithm is presented for the computation of the auxiliary weights. Many of these issues have previously been either implicitly stated or only individually addressed in various sources by a number of researchers. Besides showing simulation results and the divisionless procedure for obtaining the final auxiliary weights, a major consideration was to present all of the aforementioned concepts in a coherent and unified framework