An efficient algorithm for antenna synthesis updating following null-constraint changes

The procedure to maximise the array signal to noise ratio with null constraints involves an optimisation problem that can be solved efficiently using a modified Cholesky decomposition (UD) technique. Following changes in the main lobe and/or null positions, the optimal element weight vector can be updated without the need for a new complete matrix inversion. Some properties of the UD technique can be utilised such that the updating algorithm reprocesses only a part of the unit triangular matrix U. Proper ordering of matrix entries can minimise the dimension of the updated part.