Multiple mainbeam sidelobe cancellation architectures for constrained and/or excess degrees of freedom processing

An efficient and flexible multiple mainbeam architecture for performing adaptive sidelobe cancellation using a single set of n auxiliary antennas is described. The design can easily incorporate constrained and/or excess degrees-of-freedom processing if this proves necessary in a given application. The approach is to compute the QR decomposition of the auxiliary data matrix and then send this information to mainbeam processors, where the residual for each mainbeam is computed without explicitly calculating and applying auxiliary weights. A new fast algorithm and architecture for implementing constraints are presented. The proposed approach reduces the number of operations in the constrained mainbeam processor from order n ³ to order n²