EFFICIENT DIRECTION-FINDING METHODS EMPLOYING FORWARD-BACKWARD AVERAGING

In this paper, we develop a general approach for reducing the computat ional complexity of any direction finding method implemented with forw ard/backward (FB) averaging. We develop simplified FB data matrices in a manner paralleling previous work related to centrohermitian (correl ation) matrices. Based on these simplified data matrices, efficient co nstruction and updating of the FB correlation matrix is developed. In addition, efficient FB FFT, FB beamspace, FB EVD updating, FB SVD, and FB SVD updating methods are derived. In most cases, FB-based directio n-finding methods can be simplified so that the computational complexi ty is reduced below that of an analogous forward only implementation. Thus, effectively twice the amount of data is processed with less tota l computation.