GSC REALIZATIONS USING THE 2-DIMENSIONAL TRANSFORM-DOMAIN LMS ALGORITHM

The authors propose two new realisations of the broadband generalised sidelobe canceller (GSC) which are based on a two-dimensional (2D) ext ension of the transform-domain LMS algorithm. In the first realisation , the tap-input matrix of the GSC (following the blocking network) is mapped into the transform-domain via a 2D unitary image transform. Fol lowing this step, the transformed data are weighted and summed to prod uce the GSC output and the processor weights are updated via the self- orthogonalising LMS algorithm in the transform-domain. The second real isation uses a separable 2D transform and provides a narrowband decomp osition of the GSC. The computational complexity of these new GSC real isations is analysed and shown to be comparable to that of the fast FL MS-GSC recently proposed by Chen and Fang. However, as demonstrated by computer simulations, the new GSC realisations have a much faster con vergence rate than the FLMS-GSC when the eigenvalue spread of the tap- input correlation matrix is large.