QRD-LSL Adaptive Alogrithms Suitable for Fixed-Point Implementation

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.