Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: On Extended RLS Lattice Adaptive Variants: Error-Feedback, Normalized, and Array-Based Recursions Ricardo Merched | EURASIP Journal on Applied Signal Processing 2005 8 1235-1250 2005 Hindawi Publishing Corporation On Extended RLS Lattice Adaptive Variants Error-Feedback Normalized and Array-Based Recursions Ricardo Merched Signal Processing Laboratory LPS Department of Electronics and Computer Engineering Federal University of Rio de Janeiro . Box 68504 Rio de Janeiro RJ 21945-970 Brazil Email merched@ Received 12 May 2004 Revised 10 November 2004 Recommended for Publication by Hideaki Sakai Error-feedback normalized and array-based recursions represent equivalent RLS lattice adaptive filters which are known to offer better numerical properties under finite-precision implementations. This is the case when the underlying data structure arises from a tapped-delay-line model for the input signal. On the other hand in the context of a more general orthonormality-based input model these variants have not yet been derived and their behavior under finite precision is unknown. This paper develops several lattice structures for the exponentially weighted RLS problem under orthonormality-based data structures including errorfeedback normalized and array-based forms. As a result besides nonminimality of the new recursions they present unstable modes as well as hyperbolic rotations so that the well-known good numerical properties observed in the case of FIR models no longer exist. We verify via simulations that compared to the standard extended lattice equations these variants do not improve the robustness to quantization unlike what is normally expected for FIR models. Keywords and phrases RLS algorithm orthonormal model lattice regularized least squares. 1. INTRODUCTION In a recent paper 1 a new framework for exploiting data structure in recursive-least-squares RLS problems has been introduced. As a result we have shown how to derive RLS lattice recursions for more general orthonormal networks other than tapped-delay-line implementations 2 . As is well known the original .
