An Improved Fast Algorithm for Computing the MMSE Decision-Feedback Equalizer

摘要

This paper presents an improved version of the fast algorithm in [1] for computing the minimum mean-square-error decision-feedback equalizer (MMSE-DFE). By using the framework of QR updating, we first show a much simpler derivation of the fast algorithm. Then we present some improvements of the algorithm, making it more regular and modular. We show that we are able to directly compute the feedforward and feedback filter by Givens rotations without back-substitution and matrix-vector multiplication.