Method and device for calculating coefficients of feed-forward equalizer and feed-backward equalizer in decision feedback equalizer

摘要

A method for calculating a feed forward equalizer coefficient of a feed forward equalizer in a minimum mean square error decision feedback equalizer (MMSE-DFE) based on a fast transversal recursive least squares (FT-RLS) algorithm is provided. The length of the feed-forward equalizer is LF, which is a positive integer. The method includes an outer iteration having an LF number of iterations. The outer iteration includes an inner iteration having an n number of iterations, where n is an integer between 0 and (LF−2).

主权项

1. A method for calculating a feed-forward equalizer (FFE) coefficient of an FFE in a minimum mean square error decision feedback equalizer (MMSE-DFE) based on a fast transversal recursive squares (FT-RLS) algorithm, the FFE having a length LF, LF being a positive integer, the method comprising:
a) generating a channel impulse response (CIR) estimation vector h according to an input signal of the FFE; b) generating a priori forward prediction error φ according to the CIR estimation vector h and a forward prediction coefficient vector w; c) providing a minimum cost of forward prediction α; d) generating a normalized gain vector c according to the forward prediction coefficient vector w, the minimum cost of forward prediction α and the priori forward prediction error φ, wherein the normalized gain vector c includes elements c[0] to c[LF]; e) providing a posteriori forward prediction error ψ f) updating the forward prediction coefficient vector w according to the posteriori forward prediction error ψ and the normalized gain vector c; g) providing a conversion factor γ; h) generating the FFE coefficient according to the conversion factor γ and the normalized gain vector c; and updating the FFE with said FFE coefficient; wherein, step (a) to step (g) are collectively a 1st iteration operation and have an LF number of iterations; step (d) is a 2nd iteration operation having an n number of iterations, and wherein in the Nth iteration of the LF iterations of the 1st iteration operation, the number of iterations of the 2nd iteration operation n equals N−1; the 2nd iteration operation computes the elements c[1] to c[N−1], and directly sets the elements c[N] to c[LF] to 0 instead of computing the elements c[N] to c[LF].