QRD-LSL Adaptive Alogrithms Suitable for Fixed-Point Implementation

Abstract

In a previous study we proposed a modified version of the recursive least-square (RLS) adaptive algorithm suitable for fixed-point implementation. Using an asymptotically unbiased estimator for the algorithm's cost function we reduced the dynamic range of this parameter. In this paper, we extend the procedure for the case of QR-decomposition-based least-squares lattice (QRD-LSL) adaptive algorithm, a "fast" member of RLS family, with good numerical properties. The reduced dynamics of the algorithm’s parameters leads to facility for fixed-point implementation. The simulations performed on a fixed-point digital signal processor (DSP) sustain the practical aspects of the theoretical findings.